diff options
author | Michael Drake <tlsa@netsurf-browser.org> | 2021-04-24 16:56:49 +0100 |
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committer | Michael Drake <tlsa@netsurf-browser.org> | 2021-04-24 16:56:49 +0100 |
commit | f29bbfbc5cbfe36a0f4f98d84bf1f84d6e4ee1d4 (patch) | |
tree | 7f3d8d58ee80de3258f9285916c8b475ad954c2b | |
parent | 7253a5b36f0f07757b99895572ceac0c95022a4e (diff) | |
download | libnsgif-f29bbfbc5cbfe36a0f4f98d84bf1f84d6e4ee1d4.tar.gz libnsgif-f29bbfbc5cbfe36a0f4f98d84bf1f84d6e4ee1d4.tar.bz2 |
gif: Whitespace fixes.
Tabs for indent, spaces for alignment.
-rw-r--r-- | src/libnsgif.c | 2219 |
1 files changed, 1109 insertions, 1110 deletions
diff --git a/src/libnsgif.c b/src/libnsgif.c index 6d78dc2..5fa9cb6 100644 --- a/src/libnsgif.c +++ b/src/libnsgif.c @@ -79,21 +79,21 @@ */ static gif_result gif_initialise_sprite(gif_animation *gif, - unsigned int width, - unsigned int height) + unsigned int width, + unsigned int height) { - /* Already allocated? */ - if (gif->frame_image) { - return GIF_OK; - } - - assert(gif->bitmap_callbacks.bitmap_create); - gif->frame_image = gif->bitmap_callbacks.bitmap_create(width, height); - if (gif->frame_image == NULL) { - return GIF_INSUFFICIENT_MEMORY; - } - - return GIF_OK; + /* Already allocated? */ + if (gif->frame_image) { + return GIF_OK; + } + + assert(gif->bitmap_callbacks.bitmap_create); + gif->frame_image = gif->bitmap_callbacks.bitmap_create(width, height); + if (gif->frame_image == NULL) { + return GIF_INSUFFICIENT_MEMORY; + } + + return GIF_OK; } @@ -108,117 +108,117 @@ gif_initialise_sprite(gif_animation *gif, static gif_result gif_initialise_frame_extensions(gif_animation *gif, const int frame) { - unsigned char *gif_data, *gif_end; - int gif_bytes; - unsigned int block_size; - - /* Get our buffer position etc. */ - gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position); - gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size); - - /* Initialise the extensions */ - while (gif_data < gif_end && gif_data[0] == GIF_EXTENSION_INTRODUCER) { - ++gif_data; - if ((gif_bytes = (gif_end - gif_data)) < 1) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - - /* Switch on extension label */ - switch (gif_data[0]) { - case GIF_EXTENSION_GRAPHIC_CONTROL: - /* 6-byte Graphic Control Extension is: - * - * +0 CHAR Graphic Control Label - * +1 CHAR Block Size - * +2 CHAR __Packed Fields__ - * 3BITS Reserved - * 3BITS Disposal Method - * 1BIT User Input Flag - * 1BIT Transparent Color Flag - * +3 SHORT Delay Time - * +5 CHAR Transparent Color Index - */ - if (gif_bytes < 6) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - - gif->frames[frame].frame_delay = gif_data[3] | (gif_data[4] << 8); - if (gif_data[2] & GIF_TRANSPARENCY_MASK) { - gif->frames[frame].transparency = true; - gif->frames[frame].transparency_index = gif_data[5]; - } - gif->frames[frame].disposal_method = ((gif_data[2] & GIF_DISPOSAL_MASK) >> 2); - /* I have encountered documentation and GIFs in the - * wild that use 0x04 to restore the previous frame, - * rather than the officially documented 0x03. I - * believe some (older?) software may even actually - * export this way. We handle this as a type of - * "quirks" mode. - */ - if (gif->frames[frame].disposal_method == GIF_FRAME_QUIRKS_RESTORE) { - gif->frames[frame].disposal_method = GIF_FRAME_RESTORE; - } - gif_data += (2 + gif_data[1]); - break; - - case GIF_EXTENSION_APPLICATION: - /* 14-byte+ Application Extension is: - * - * +0 CHAR Application Extension Label - * +1 CHAR Block Size - * +2 8CHARS Application Identifier - * +10 3CHARS Appl. Authentication Code - * +13 1-256 Application Data (Data sub-blocks) - */ - if (gif_bytes < 17) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - if ((gif_data[1] == 0x0b) && - (strncmp((const char *) gif_data + 2, - "NETSCAPE2.0", 11) == 0) && - (gif_data[13] == 0x03) && - (gif_data[14] == 0x01)) { - gif->loop_count = gif_data[15] | (gif_data[16] << 8); - } - gif_data += (2 + gif_data[1]); - break; - - case GIF_EXTENSION_COMMENT: - /* Move the pointer to the first data sub-block Skip 1 - * byte for the extension label - */ - ++gif_data; - break; - - default: - /* Move the pointer to the first data sub-block Skip 2 - * bytes for the extension label and size fields Skip - * the extension size itself - */ - if (gif_bytes < 2) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - gif_data += (2 + gif_data[1]); - } - - /* Repeatedly skip blocks until we get a zero block or run out - * of data This data is ignored by this gif decoder - */ - gif_bytes = (gif_end - gif_data); - block_size = 0; - while (gif_data < gif_end && gif_data[0] != GIF_BLOCK_TERMINATOR) { - block_size = gif_data[0] + 1; - if ((gif_bytes -= block_size) < 0) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - gif_data += block_size; - } - ++gif_data; - } - - /* Set buffer position and return */ - gif->buffer_position = (gif_data - gif->gif_data); - return GIF_OK; + unsigned char *gif_data, *gif_end; + int gif_bytes; + unsigned int block_size; + + /* Get our buffer position etc. */ + gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position); + gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size); + + /* Initialise the extensions */ + while (gif_data < gif_end && gif_data[0] == GIF_EXTENSION_INTRODUCER) { + ++gif_data; + if ((gif_bytes = (gif_end - gif_data)) < 1) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + + /* Switch on extension label */ + switch (gif_data[0]) { + case GIF_EXTENSION_GRAPHIC_CONTROL: + /* 6-byte Graphic Control Extension is: + * + * +0 CHAR Graphic Control Label + * +1 CHAR Block Size + * +2 CHAR __Packed Fields__ + * 3BITS Reserved + * 3BITS Disposal Method + * 1BIT User Input Flag + * 1BIT Transparent Color Flag + * +3 SHORT Delay Time + * +5 CHAR Transparent Color Index + */ + if (gif_bytes < 6) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + + gif->frames[frame].frame_delay = gif_data[3] | (gif_data[4] << 8); + if (gif_data[2] & GIF_TRANSPARENCY_MASK) { + gif->frames[frame].transparency = true; + gif->frames[frame].transparency_index = gif_data[5]; + } + gif->frames[frame].disposal_method = ((gif_data[2] & GIF_DISPOSAL_MASK) >> 2); + /* I have encountered documentation and GIFs in the + * wild that use 0x04 to restore the previous frame, + * rather than the officially documented 0x03. I + * believe some (older?) software may even actually + * export this way. We handle this as a type of + * "quirks" mode. + */ + if (gif->frames[frame].disposal_method == GIF_FRAME_QUIRKS_RESTORE) { + gif->frames[frame].disposal_method = GIF_FRAME_RESTORE; + } + gif_data += (2 + gif_data[1]); + break; + + case GIF_EXTENSION_APPLICATION: + /* 14-byte+ Application Extension is: + * + * +0 CHAR Application Extension Label + * +1 CHAR Block Size + * +2 8CHARS Application Identifier + * +10 3CHARS Appl. Authentication Code + * +13 1-256 Application Data (Data sub-blocks) + */ + if (gif_bytes < 17) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + if ((gif_data[1] == 0x0b) && + (strncmp((const char *) gif_data + 2, + "NETSCAPE2.0", 11) == 0) && + (gif_data[13] == 0x03) && + (gif_data[14] == 0x01)) { + gif->loop_count = gif_data[15] | (gif_data[16] << 8); + } + gif_data += (2 + gif_data[1]); + break; + + case GIF_EXTENSION_COMMENT: + /* Move the pointer to the first data sub-block Skip 1 + * byte for the extension label + */ + ++gif_data; + break; + + default: + /* Move the pointer to the first data sub-block Skip 2 + * bytes for the extension label and size fields Skip + * the extension size itself + */ + if (gif_bytes < 2) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + gif_data += (2 + gif_data[1]); + } + + /* Repeatedly skip blocks until we get a zero block or run out + * of data This data is ignored by this gif decoder + */ + gif_bytes = (gif_end - gif_data); + block_size = 0; + while (gif_data < gif_end && gif_data[0] != GIF_BLOCK_TERMINATOR) { + block_size = gif_data[0] + 1; + if ((gif_bytes -= block_size) < 0) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + gif_data += block_size; + } + ++gif_data; + } + + /* Set buffer position and return */ + gif->buffer_position = (gif_data - gif->gif_data); + return GIF_OK; } @@ -237,231 +237,230 @@ gif_initialise_frame_extensions(gif_animation *gif, const int frame) */ static gif_result gif_initialise_frame(gif_animation *gif) { - int frame; - gif_frame *temp_buf; - - unsigned char *gif_data, *gif_end; - int gif_bytes; - unsigned int flags = 0; - unsigned int width, height, offset_x, offset_y; - unsigned int block_size, colour_table_size; - bool first_image = true; - gif_result return_value; - - /* Get the frame to decode and our data position */ - frame = gif->frame_count; - - /* Get our buffer position etc. */ - gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position); - gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size); - gif_bytes = (gif_end - gif_data); - - /* Check if we've finished */ - if ((gif_bytes > 0) && (gif_data[0] == GIF_TRAILER)) { - return GIF_OK; - } - - /* Check if there is enough data remaining. The shortest block of data - * is a 4-byte comment extension + 1-byte block terminator + 1-byte gif - * trailer - */ - if (gif_bytes < 6) { - return GIF_INSUFFICIENT_DATA; - } - - /* We could theoretically get some junk data that gives us millions of - * frames, so we ensure that we don't have a silly number - */ - if (frame > 4096) { - return GIF_FRAME_DATA_ERROR; - } - - /* Get some memory to store our pointers in etc. */ - if ((int)gif->frame_holders <= frame) { - /* Allocate more memory */ - temp_buf = (gif_frame *)realloc(gif->frames, (frame + 1) * sizeof(gif_frame)); - if (temp_buf == NULL) { - return GIF_INSUFFICIENT_MEMORY; - } - gif->frames = temp_buf; - gif->frame_holders = frame + 1; - } - - /* Store our frame pointer. We would do it when allocating except we - * start off with one frame allocated so we can always use realloc. - */ - gif->frames[frame].frame_pointer = gif->buffer_position; - gif->frames[frame].display = false; - gif->frames[frame].virgin = true; - gif->frames[frame].disposal_method = 0; - gif->frames[frame].transparency = false; - gif->frames[frame].frame_delay = 100; - gif->frames[frame].redraw_required = false; - - /* Invalidate any previous decoding we have of this frame */ - if (gif->decoded_frame == frame) { - gif->decoded_frame = GIF_INVALID_FRAME; - } - - /* We pretend to initialise the frames, but really we just skip over - * all the data contained within. This is all basically a cut down - * version of gif_decode_frame that doesn't have any of the LZW bits in - * it. - */ - - /* Initialise any extensions */ - gif->buffer_position = gif_data - gif->gif_data; - return_value = gif_initialise_frame_extensions(gif, frame); - if (return_value != GIF_OK) { - return return_value; - } - gif_data = (gif->gif_data + gif->buffer_position); - gif_bytes = (gif_end - gif_data); - - /* Check if we've finished */ - if ((gif_bytes = (gif_end - gif_data)) < 1) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - - if (gif_data[0] == GIF_TRAILER) { - gif->buffer_position = (gif_data - gif->gif_data); - gif->frame_count = frame + 1; - return GIF_OK; - } - - /* If we're not done, there should be an image descriptor */ - if (gif_data[0] != GIF_IMAGE_SEPARATOR) { - return GIF_FRAME_DATA_ERROR; - } - - /* Do some simple boundary checking */ - if (gif_bytes < 10) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - offset_x = gif_data[1] | (gif_data[2] << 8); - offset_y = gif_data[3] | (gif_data[4] << 8); - width = gif_data[5] | (gif_data[6] << 8); - height = gif_data[7] | (gif_data[8] << 8); - - /* Set up the redraw characteristics. We have to check for extending - * the area due to multi-image frames. - */ - if (!first_image) { - if (gif->frames[frame].redraw_x > offset_x) { - gif->frames[frame].redraw_width += (gif->frames[frame].redraw_x - offset_x); - gif->frames[frame].redraw_x = offset_x; - } - - if (gif->frames[frame].redraw_y > offset_y) { - gif->frames[frame].redraw_height += (gif->frames[frame].redraw_y - offset_y); - gif->frames[frame].redraw_y = offset_y; - } - - if ((offset_x + width) > (gif->frames[frame].redraw_x + gif->frames[frame].redraw_width)) { - gif->frames[frame].redraw_width = (offset_x + width) - gif->frames[frame].redraw_x; - } - - if ((offset_y + height) > (gif->frames[frame].redraw_y + gif->frames[frame].redraw_height)) { - gif->frames[frame].redraw_height = (offset_y + height) - gif->frames[frame].redraw_y; - } - } else { - first_image = false; - gif->frames[frame].redraw_x = offset_x; - gif->frames[frame].redraw_y = offset_y; - gif->frames[frame].redraw_width = width; - gif->frames[frame].redraw_height = height; - } - - /* if we are clearing the background then we need to redraw enough to - * cover the previous frame too - */ - gif->frames[frame].redraw_required = ((gif->frames[frame].disposal_method == GIF_FRAME_CLEAR) || - (gif->frames[frame].disposal_method == GIF_FRAME_RESTORE)); - - /* Frame size may have grown. - */ - gif->width = (offset_x + width > gif->width) ? - offset_x + width : gif->width; - gif->height = (offset_y + height > gif->height) ? - offset_y + height : gif->height; - - /* Decode the flags */ - flags = gif_data[9]; - colour_table_size = 2 << (flags & GIF_COLOUR_TABLE_SIZE_MASK); - - /* Move our data onwards and remember we've got a bit of this frame */ - gif_data += 10; - gif_bytes = (gif_end - gif_data); - gif->frame_count_partial = frame + 1; - - /* Skip the local colour table */ - if (flags & GIF_COLOUR_TABLE_MASK) { - gif_data += 3 * colour_table_size; - if ((gif_bytes = (gif_end - gif_data)) < 0) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - } - - /* Ensure we have a correct code size */ - if (gif_bytes < 1) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - if (gif_data[0] >= LZW_CODE_MAX) { - return GIF_DATA_ERROR; - } - - /* Move our pointer to the actual image data */ - gif_data++; - --gif_bytes; - - /* Repeatedly skip blocks until we get a zero block or run out of data - * These blocks of image data are processed later by gif_decode_frame() - */ - block_size = 0; - while (block_size != 1) { - if (gif_bytes < 1) return GIF_INSUFFICIENT_FRAME_DATA; - block_size = gif_data[0] + 1; - /* Check if the frame data runs off the end of the file */ - if ((int)(gif_bytes - block_size) < 0) { - /* Try to recover by signaling the end of the gif. - * Once we get garbage data, there is no logical way to - * determine where the next frame is. It's probably - * better to partially load the gif than not at all. - */ - if (gif_bytes >= 2) { - gif_data[0] = 0; - gif_data[1] = GIF_TRAILER; - gif_bytes = 1; - ++gif_data; - break; - } else { - return GIF_INSUFFICIENT_FRAME_DATA; - } - } else { - gif_bytes -= block_size; - gif_data += block_size; - } - } - - /* Add the frame and set the display flag */ - gif->buffer_position = gif_data - gif->gif_data; - gif->frame_count = frame + 1; - gif->frames[frame].display = true; - - /* Check if we've finished */ - if (gif_bytes < 1) { - return GIF_INSUFFICIENT_FRAME_DATA; - } else { - if (gif_data[0] == GIF_TRAILER) { - return GIF_OK; - } - } - return GIF_WORKING; + int frame; + gif_frame *temp_buf; + + unsigned char *gif_data, *gif_end; + int gif_bytes; + unsigned int flags = 0; + unsigned int width, height, offset_x, offset_y; + unsigned int block_size, colour_table_size; + bool first_image = true; + gif_result return_value; + + /* Get the frame to decode and our data position */ + frame = gif->frame_count; + + /* Get our buffer position etc. */ + gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position); + gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size); + gif_bytes = (gif_end - gif_data); + + /* Check if we've finished */ + if ((gif_bytes > 0) && (gif_data[0] == GIF_TRAILER)) { + return GIF_OK; + } + + /* Check if there is enough data remaining. The shortest block of data + * is a 4-byte comment extension + 1-byte block terminator + 1-byte gif + * trailer + */ + if (gif_bytes < 6) { + return GIF_INSUFFICIENT_DATA; + } + + /* We could theoretically get some junk data that gives us millions of + * frames, so we ensure that we don't have a silly number + */ + if (frame > 4096) { + return GIF_FRAME_DATA_ERROR; + } + + /* Get some memory to store our pointers in etc. */ + if ((int)gif->frame_holders <= frame) { + /* Allocate more memory */ + temp_buf = (gif_frame *)realloc(gif->frames, (frame + 1) * sizeof(gif_frame)); + if (temp_buf == NULL) { + return GIF_INSUFFICIENT_MEMORY; + } + gif->frames = temp_buf; + gif->frame_holders = frame + 1; + } + + /* Store our frame pointer. We would do it when allocating except we + * start off with one frame allocated so we can always use realloc. + */ + gif->frames[frame].frame_pointer = gif->buffer_position; + gif->frames[frame].display = false; + gif->frames[frame].virgin = true; + gif->frames[frame].disposal_method = 0; + gif->frames[frame].transparency = false; + gif->frames[frame].frame_delay = 100; + gif->frames[frame].redraw_required = false; + + /* Invalidate any previous decoding we have of this frame */ + if (gif->decoded_frame == frame) { + gif->decoded_frame = GIF_INVALID_FRAME; + } + + /* We pretend to initialise the frames, but really we just skip over + * all the data contained within. This is all basically a cut down + * version of gif_decode_frame that doesn't have any of the LZW bits in + * it. + */ + + /* Initialise any extensions */ + gif->buffer_position = gif_data - gif->gif_data; + return_value = gif_initialise_frame_extensions(gif, frame); + if (return_value != GIF_OK) { + return return_value; + } + gif_data = (gif->gif_data + gif->buffer_position); + gif_bytes = (gif_end - gif_data); + + /* Check if we've finished */ + if ((gif_bytes = (gif_end - gif_data)) < 1) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + + if (gif_data[0] == GIF_TRAILER) { + gif->buffer_position = (gif_data - gif->gif_data); + gif->frame_count = frame + 1; + return GIF_OK; + } + + /* If we're not done, there should be an image descriptor */ + if (gif_data[0] != GIF_IMAGE_SEPARATOR) { + return GIF_FRAME_DATA_ERROR; + } + + /* Do some simple boundary checking */ + if (gif_bytes < 10) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + offset_x = gif_data[1] | (gif_data[2] << 8); + offset_y = gif_data[3] | (gif_data[4] << 8); + width = gif_data[5] | (gif_data[6] << 8); + height = gif_data[7] | (gif_data[8] << 8); + + /* Set up the redraw characteristics. We have to check for extending + * the area due to multi-image frames. + */ + if (!first_image) { + if (gif->frames[frame].redraw_x > offset_x) { + gif->frames[frame].redraw_width += (gif->frames[frame].redraw_x - offset_x); + gif->frames[frame].redraw_x = offset_x; + } + + if (gif->frames[frame].redraw_y > offset_y) { + gif->frames[frame].redraw_height += (gif->frames[frame].redraw_y - offset_y); + gif->frames[frame].redraw_y = offset_y; + } + + if ((offset_x + width) > (gif->frames[frame].redraw_x + gif->frames[frame].redraw_width)) { + gif->frames[frame].redraw_width = (offset_x + width) - gif->frames[frame].redraw_x; + } + + if ((offset_y + height) > (gif->frames[frame].redraw_y + gif->frames[frame].redraw_height)) { + gif->frames[frame].redraw_height = (offset_y + height) - gif->frames[frame].redraw_y; + } + } else { + first_image = false; + gif->frames[frame].redraw_x = offset_x; + gif->frames[frame].redraw_y = offset_y; + gif->frames[frame].redraw_width = width; + gif->frames[frame].redraw_height = height; + } + + /* if we are clearing the background then we need to redraw enough to + * cover the previous frame too + */ + gif->frames[frame].redraw_required = + ((gif->frames[frame].disposal_method == GIF_FRAME_CLEAR) || + (gif->frames[frame].disposal_method == GIF_FRAME_RESTORE)); + + /* Frame size may have grown. + */ + gif->width = (offset_x + width > gif->width) ? + offset_x + width : gif->width; + gif->height = (offset_y + height > gif->height) ? + offset_y + height : gif->height; + + /* Decode the flags */ + flags = gif_data[9]; + colour_table_size = 2 << (flags & GIF_COLOUR_TABLE_SIZE_MASK); + + /* Move our data onwards and remember we've got a bit of this frame */ + gif_data += 10; + gif_bytes = (gif_end - gif_data); + gif->frame_count_partial = frame + 1; + + /* Skip the local colour table */ + if (flags & GIF_COLOUR_TABLE_MASK) { + gif_data += 3 * colour_table_size; + if ((gif_bytes = (gif_end - gif_data)) < 0) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + } + + /* Ensure we have a correct code size */ + if (gif_bytes < 1) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + if (gif_data[0] >= LZW_CODE_MAX) { + return GIF_DATA_ERROR; + } + + /* Move our pointer to the actual image data */ + gif_data++; + --gif_bytes; + + /* Repeatedly skip blocks until we get a zero block or run out of data + * These blocks of image data are processed later by gif_decode_frame() + */ + block_size = 0; + while (block_size != 1) { + if (gif_bytes < 1) return GIF_INSUFFICIENT_FRAME_DATA; + block_size = gif_data[0] + 1; + /* Check if the frame data runs off the end of the file */ + if ((int)(gif_bytes - block_size) < 0) { + /* Try to recover by signaling the end of the gif. + * Once we get garbage data, there is no logical way to + * determine where the next frame is. It's probably + * better to partially load the gif than not at all. + */ + if (gif_bytes >= 2) { + gif_data[0] = 0; + gif_data[1] = GIF_TRAILER; + gif_bytes = 1; + ++gif_data; + break; + } else { + return GIF_INSUFFICIENT_FRAME_DATA; + } + } else { + gif_bytes -= block_size; + gif_data += block_size; + } + } + + /* Add the frame and set the display flag */ + gif->buffer_position = gif_data - gif->gif_data; + gif->frame_count = frame + 1; + gif->frames[frame].display = true; + + /* Check if we've finished */ + if (gif_bytes < 1) { + return GIF_INSUFFICIENT_FRAME_DATA; + } else { + if (gif_data[0] == GIF_TRAILER) { + return GIF_OK; + } + } + return GIF_WORKING; } - - /** * Skips the frame's extensions (which have been previously initialised) * @@ -471,313 +470,313 @@ static gif_result gif_initialise_frame(gif_animation *gif) */ static gif_result gif_skip_frame_extensions(gif_animation *gif) { - unsigned char *gif_data, *gif_end; - int gif_bytes; - unsigned int block_size; - - /* Get our buffer position etc. */ - gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position); - gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size); - gif_bytes = (gif_end - gif_data); - - /* Skip the extensions */ - while (gif_data < gif_end && gif_data[0] == GIF_EXTENSION_INTRODUCER) { - ++gif_data; - if (gif_data >= gif_end) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - - /* Switch on extension label */ - switch(gif_data[0]) { - case GIF_EXTENSION_COMMENT: - /* Move the pointer to the first data sub-block - * 1 byte for the extension label - */ - ++gif_data; - break; - - default: - /* Move the pointer to the first data sub-block 2 bytes - * for the extension label and size fields Skip the - * extension size itself - */ - if (gif_data + 1 >= gif_end) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - gif_data += (2 + gif_data[1]); - } - - /* Repeatedly skip blocks until we get a zero block or run out - * of data This data is ignored by this gif decoder - */ - gif_bytes = (gif_end - gif_data); - block_size = 0; - while (gif_data < gif_end && gif_data[0] != GIF_BLOCK_TERMINATOR) { - block_size = gif_data[0] + 1; - if ((gif_bytes -= block_size) < 0) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - gif_data += block_size; - } - ++gif_data; - } - - /* Set buffer position and return */ - gif->buffer_position = (gif_data - gif->gif_data); - return GIF_OK; + unsigned char *gif_data, *gif_end; + int gif_bytes; + unsigned int block_size; + + /* Get our buffer position etc. */ + gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position); + gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size); + gif_bytes = (gif_end - gif_data); + + /* Skip the extensions */ + while (gif_data < gif_end && gif_data[0] == GIF_EXTENSION_INTRODUCER) { + ++gif_data; + if (gif_data >= gif_end) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + + /* Switch on extension label */ + switch(gif_data[0]) { + case GIF_EXTENSION_COMMENT: + /* Move the pointer to the first data sub-block + * 1 byte for the extension label + */ + ++gif_data; + break; + + default: + /* Move the pointer to the first data sub-block 2 bytes + * for the extension label and size fields Skip the + * extension size itself + */ + if (gif_data + 1 >= gif_end) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + gif_data += (2 + gif_data[1]); + } + + /* Repeatedly skip blocks until we get a zero block or run out + * of data This data is ignored by this gif decoder + */ + gif_bytes = (gif_end - gif_data); + block_size = 0; + while (gif_data < gif_end && gif_data[0] != GIF_BLOCK_TERMINATOR) { + block_size = gif_data[0] + 1; + if ((gif_bytes -= block_size) < 0) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + gif_data += block_size; + } + ++gif_data; + } + + /* Set buffer position and return */ + gif->buffer_position = (gif_data - gif->gif_data); + return GIF_OK; } static unsigned int gif_interlaced_line(int height, int y) { - if ((y << 3) < height) { - return (y << 3); - } - y -= ((height + 7) >> 3); - if ((y << 3) < (height - 4)) { - return (y << 3) + 4; - } - y -= ((height + 3) >> 3); - if ((y << 2) < (height - 2)) { - return (y << 2) + 2; - } - y -= ((height + 1) >> 2); - return (y << 1) + 1; + if ((y << 3) < height) { + return (y << 3); + } + y -= ((height + 7) >> 3); + if ((y << 3) < (height - 4)) { + return (y << 3) + 4; + } + y -= ((height + 3) >> 3); + if ((y << 2) < (height - 2)) { + return (y << 2) + 2; + } + y -= ((height + 1) >> 2); + return (y << 1) + 1; } static gif_result gif_error_from_lzw(lzw_result l_res) { - static const gif_result g_res[] = { - [LZW_OK] = GIF_OK, - [LZW_OK_EOD] = GIF_END_OF_FRAME, - [LZW_NO_MEM] = GIF_INSUFFICIENT_MEMORY, - [LZW_NO_DATA] = GIF_INSUFFICIENT_FRAME_DATA, - [LZW_EOI_CODE] = GIF_FRAME_DATA_ERROR, - [LZW_BAD_ICODE] = GIF_FRAME_DATA_ERROR, - [LZW_BAD_CODE] = GIF_FRAME_DATA_ERROR, - }; - return g_res[l_res]; + static const gif_result g_res[] = { + [LZW_OK] = GIF_OK, + [LZW_OK_EOD] = GIF_END_OF_FRAME, + [LZW_NO_MEM] = GIF_INSUFFICIENT_MEMORY, + [LZW_NO_DATA] = GIF_INSUFFICIENT_FRAME_DATA, + [LZW_EOI_CODE] = GIF_FRAME_DATA_ERROR, + [LZW_BAD_ICODE] = GIF_FRAME_DATA_ERROR, + [LZW_BAD_CODE] = GIF_FRAME_DATA_ERROR, + }; + return g_res[l_res]; } static void gif__record_previous_frame(gif_animation *gif) { - bool need_alloc = gif->prev_frame == NULL; - const uint32_t *frame_data; - uint32_t *prev_frame; - - if (gif->decoded_frame == GIF_INVALID_FRAME || - gif->decoded_frame == gif->prev_index) { - /* No frame to copy, or already have this frame recorded. */ - return; - } - - assert(gif->bitmap_callbacks.bitmap_get_buffer); - frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image); - if (!frame_data) { - return; - } - - if (gif->prev_frame != NULL && - gif->width * gif->height > gif->prev_width * gif->prev_height) { - need_alloc = true; - } - - if (need_alloc) { - prev_frame = realloc(gif->prev_frame, - gif->width * gif->height * 4); - if (prev_frame == NULL) { - return; - } - } else { - prev_frame = gif->prev_frame; - } - - memcpy(prev_frame, frame_data, gif->width * gif->height * 4); - - gif->prev_frame = prev_frame; - gif->prev_width = gif->width; - gif->prev_height = gif->height; - gif->prev_index = gif->decoded_frame; + bool need_alloc = gif->prev_frame == NULL; + const uint32_t *frame_data; + uint32_t *prev_frame; + + if (gif->decoded_frame == GIF_INVALID_FRAME || + gif->decoded_frame == gif->prev_index) { + /* No frame to copy, or already have this frame recorded. */ + return; + } + + assert(gif->bitmap_callbacks.bitmap_get_buffer); + frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image); + if (!frame_data) { + return; + } + + if (gif->prev_frame != NULL && + gif->width * gif->height > gif->prev_width * gif->prev_height) { + need_alloc = true; + } + + if (need_alloc) { + prev_frame = realloc(gif->prev_frame, + gif->width * gif->height * 4); + if (prev_frame == NULL) { + return; + } + } else { + prev_frame = gif->prev_frame; + } + + memcpy(prev_frame, frame_data, gif->width * gif->height * 4); + + gif->prev_frame = prev_frame; + gif->prev_width = gif->width; + gif->prev_height = gif->height; + gif->prev_index = gif->decoded_frame; } static gif_result gif__recover_previous_frame(const gif_animation *gif) { - const uint32_t *prev_frame = gif->prev_frame; - unsigned height = gif->height < gif->prev_height ? gif->height : gif->prev_height; - unsigned width = gif->width < gif->prev_width ? gif->width : gif->prev_width; - uint32_t *frame_data; + const uint32_t *prev_frame = gif->prev_frame; + unsigned height = gif->height < gif->prev_height ? gif->height : gif->prev_height; + unsigned width = gif->width < gif->prev_width ? gif->width : gif->prev_width; + uint32_t *frame_data; - if (prev_frame == NULL) { - return GIF_FRAME_DATA_ERROR; - } + if (prev_frame == NULL) { + return GIF_FRAME_DATA_ERROR; + } - assert(gif->bitmap_callbacks.bitmap_get_buffer); - frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image); - if (!frame_data) { - return GIF_INSUFFICIENT_MEMORY; - } + assert(gif->bitmap_callbacks.bitmap_get_buffer); + frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image); + if (!frame_data) { + return GIF_INSUFFICIENT_MEMORY; + } - for (unsigned y = 0; y < height; y++) { - memcpy(frame_data, prev_frame, width * 4); + for (unsigned y = 0; y < height; y++) { + memcpy(frame_data, prev_frame, width * 4); - frame_data += gif->width; - prev_frame += gif->prev_width; - } + frame_data += gif->width; + prev_frame += gif->prev_width; + } - return GIF_OK; + return GIF_OK; } static gif_result gif__decode_complex(gif_animation *gif, - unsigned int frame, - unsigned int width, - unsigned int height, - unsigned int offset_x, - unsigned int offset_y, - unsigned int interlace, - uint8_t minimum_code_size, - unsigned int *restrict frame_data, - unsigned int *restrict colour_table) + unsigned int frame, + unsigned int width, + unsigned int height, + unsigned int offset_x, + unsigned int offset_y, + unsigned int interlace, + uint8_t minimum_code_size, + unsigned int *restrict frame_data, + unsigned int *restrict colour_table) { - unsigned int transparency_index; - uint32_t available = 0; - gif_result ret = GIF_OK; - lzw_result res; - - /* Initialise the LZW decoding */ - res = lzw_decode_init(gif->lzw_ctx, gif->gif_data, - gif->buffer_size, gif->buffer_position, - minimum_code_size); - if (res != LZW_OK) { - return gif_error_from_lzw(res); - } - - transparency_index = gif->frames[frame].transparency ? - gif->frames[frame].transparency_index : - GIF_NO_TRANSPARENCY; - - for (unsigned int y = 0; y < height; y++) { - unsigned int x; - unsigned int decode_y; - unsigned int *frame_scanline; - - if (interlace) { - decode_y = gif_interlaced_line(height, y) + offset_y; - } else { - decode_y = y + offset_y; - } - frame_scanline = frame_data + offset_x + (decode_y * gif->width); - - x = width; - while (x > 0) { - const uint8_t *uncompressed; - unsigned row_available; - if (available == 0) { - if (res != LZW_OK) { - /* Unexpected end of frame, try to recover */ - if (res == LZW_OK_EOD) { - ret = GIF_OK; - } else { - ret = gif_error_from_lzw(res); - } - break; - } - res = lzw_decode_continuous(gif->lzw_ctx, - &uncompressed, &available); - } - - row_available = x < available ? x : available; - x -= row_available; - available -= row_available; - while (row_available-- > 0) { - register unsigned int colour; - colour = *uncompressed++; - if (colour != transparency_index) { - *frame_scanline = colour_table[colour]; - } - frame_scanline++; - } - } - } - return ret; + unsigned int transparency_index; + uint32_t available = 0; + gif_result ret = GIF_OK; + lzw_result res; + + /* Initialise the LZW decoding */ + res = lzw_decode_init(gif->lzw_ctx, gif->gif_data, + gif->buffer_size, gif->buffer_position, + minimum_code_size); + if (res != LZW_OK) { + return gif_error_from_lzw(res); + } + + transparency_index = gif->frames[frame].transparency ? + gif->frames[frame].transparency_index : + GIF_NO_TRANSPARENCY; + + for (unsigned int y = 0; y < height; y++) { + unsigned int x; + unsigned int decode_y; + unsigned int *frame_scanline; + + if (interlace) { + decode_y = gif_interlaced_line(height, y) + offset_y; + } else { + decode_y = y + offset_y; + } + frame_scanline = frame_data + offset_x + (decode_y * gif->width); + + x = width; + while (x > 0) { + const uint8_t *uncompressed; + unsigned row_available; + if (available == 0) { + if (res != LZW_OK) { + /* Unexpected end of frame, try to recover */ + if (res == LZW_OK_EOD) { + ret = GIF_OK; + } else { + ret = gif_error_from_lzw(res); + } + break; + } + res = lzw_decode_continuous(gif->lzw_ctx, + &uncompressed, &available); + } + + row_available = x < available ? x : available; + x -= row_available; + available -= row_available; + while (row_available-- > 0) { + register unsigned int colour; + colour = *uncompressed++; + if (colour != transparency_index) { + *frame_scanline = colour_table[colour]; + } + frame_scanline++; + } + } + } + return ret; } static gif_result gif__decode_simple(gif_animation *gif, - unsigned int frame, - unsigned int height, - unsigned int offset_y, - uint8_t minimum_code_size, - unsigned int *restrict frame_data, - unsigned int *restrict colour_table) + unsigned int frame, + unsigned int height, + unsigned int offset_y, + uint8_t minimum_code_size, + unsigned int *restrict frame_data, + unsigned int *restrict colour_table) { - unsigned int transparency_index; - uint32_t pixels = gif->width * height; - uint32_t written = 0; - gif_result ret = GIF_OK; - lzw_result res; - - /* Initialise the LZW decoding */ - res = lzw_decode_init(gif->lzw_ctx, gif->gif_data, - gif->buffer_size, gif->buffer_position, - minimum_code_size); - if (res != LZW_OK) { - return gif_error_from_lzw(res); - } - - transparency_index = gif->frames[frame].transparency ? - gif->frames[frame].transparency_index : - GIF_NO_TRANSPARENCY; - - frame_data += (offset_y * gif->width); - - while (pixels > 0) { - res = lzw_decode_map_continuous(gif->lzw_ctx, - transparency_index, colour_table, - frame_data, pixels, &written); - pixels -= written; - frame_data += written; - if (res != LZW_OK) { - /* Unexpected end of frame, try to recover */ - if (res == LZW_OK_EOD) { - ret = GIF_OK; - } else { - ret = gif_error_from_lzw(res); - } - break; - } - } - - if (pixels == 0) { - ret = GIF_OK; - } - - return ret; + unsigned int transparency_index; + uint32_t pixels = gif->width * height; + uint32_t written = 0; + gif_result ret = GIF_OK; + lzw_result res; + + /* Initialise the LZW decoding */ + res = lzw_decode_init(gif->lzw_ctx, gif->gif_data, + gif->buffer_size, gif->buffer_position, + minimum_code_size); + if (res != LZW_OK) { + return gif_error_from_lzw(res); + } + + transparency_index = gif->frames[frame].transparency ? + gif->frames[frame].transparency_index : + GIF_NO_TRANSPARENCY; + + frame_data += (offset_y * gif->width); + + while (pixels > 0) { + res = lzw_decode_map_continuous(gif->lzw_ctx, + transparency_index, colour_table, + frame_data, pixels, &written); + pixels -= written; + frame_data += written; + if (res != LZW_OK) { + /* Unexpected end of frame, try to recover */ + if (res == LZW_OK_EOD) { + ret = GIF_OK; + } else { + ret = gif_error_from_lzw(res); + } + break; + } + } + + if (pixels == 0) { + ret = GIF_OK; + } + + return ret; } static inline gif_result gif__decode(gif_animation *gif, - unsigned int frame, - unsigned int width, - unsigned int height, - unsigned int offset_x, - unsigned int offset_y, - unsigned int interlace, - uint8_t minimum_code_size, - unsigned int *restrict frame_data, - unsigned int *restrict colour_table) + unsigned int frame, + unsigned int width, + unsigned int height, + unsigned int offset_x, + unsigned int offset_y, + unsigned int interlace, + uint8_t minimum_code_size, + unsigned int *restrict frame_data, + unsigned int *restrict colour_table) { - gif_result ret; - - if (interlace == false && width == gif->width && offset_x == 0) { - ret = gif__decode_simple(gif, frame, height, offset_y, - minimum_code_size, frame_data, colour_table); - } else { - ret = gif__decode_complex(gif, frame, width, height, - offset_x, offset_y, interlace, - minimum_code_size, frame_data, colour_table); - } - - return ret; + gif_result ret; + + if (interlace == false && width == gif->width && offset_x == 0) { + ret = gif__decode_simple(gif, frame, height, offset_y, + minimum_code_size, frame_data, colour_table); + } else { + ret = gif__decode_complex(gif, frame, width, height, + offset_x, offset_y, interlace, + minimum_code_size, frame_data, colour_table); + } + + return ret; } /** @@ -789,527 +788,527 @@ gif__decode(gif_animation *gif, */ static gif_result gif_internal_decode_frame(gif_animation *gif, - unsigned int frame, - bool clear_image) + unsigned int frame, + bool clear_image) { - gif_result err; - unsigned int index = 0; - unsigned char *gif_data, *gif_end; - int gif_bytes; - unsigned int width, height, offset_x, offset_y; - unsigned int flags, colour_table_size, interlace; - unsigned int *colour_table; - unsigned int *frame_data = 0; // Set to 0 for no warnings - unsigned int save_buffer_position; - unsigned int return_value = 0; - - /* Ensure this frame is supposed to be decoded */ - if (gif->frames[frame].display == false) { - return GIF_OK; - } - - /* Ensure the frame is in range to decode */ - if (frame > gif->frame_count_partial) { - return GIF_INSUFFICIENT_DATA; - } - - /* done if frame is already decoded */ - if ((!clear_image) && - ((int)frame == gif->decoded_frame)) { - return GIF_OK; - } - - /* Get the start of our frame data and the end of the GIF data */ - gif_data = gif->gif_data + gif->frames[frame].frame_pointer; - gif_end = gif->gif_data + gif->buffer_size; - gif_bytes = (gif_end - gif_data); - - /* - * Ensure there is a minimal amount of data to proceed. The shortest - * block of data is a 10-byte image descriptor + 1-byte gif trailer - */ - if (gif_bytes < 12) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - - /* Save the buffer position */ - save_buffer_position = gif->buffer_position; - gif->buffer_position = gif_data - gif->gif_data; - - /* Skip any extensions because they have allready been processed */ - if ((return_value = gif_skip_frame_extensions(gif)) != GIF_OK) { - goto gif_decode_frame_exit; - } - gif_data = (gif->gif_data + gif->buffer_position); - gif_bytes = (gif_end - gif_data); - - /* Ensure we have enough data for the 10-byte image descriptor + 1-byte - * gif trailer - */ - if (gif_bytes < 12) { - return_value = GIF_INSUFFICIENT_FRAME_DATA; - goto gif_decode_frame_exit; - } - - /* 10-byte Image Descriptor is: - * - * +0 CHAR Image Separator (0x2c) - * +1 SHORT Image Left Position - * +3 SHORT Image Top Position - * +5 SHORT Width - * +7 SHORT Height - * +9 CHAR __Packed Fields__ - * 1BIT Local Colour Table Flag - * 1BIT Interlace Flag - * 1BIT Sort Flag - * 2BITS Reserved - * 3BITS Size of Local Colour Table - */ - if (gif_data[0] != GIF_IMAGE_SEPARATOR) { - return_value = GIF_DATA_ERROR; - goto gif_decode_frame_exit; - } - offset_x = gif_data[1] | (gif_data[2] << 8); - offset_y = gif_data[3] | (gif_data[4] << 8); - width = gif_data[5] | (gif_data[6] << 8); - height = gif_data[7] | (gif_data[8] << 8); - - /* Boundary checking - shouldn't ever happen except unless the data has - * been modified since initialisation. - */ - if ((offset_x + width > gif->width) || - (offset_y + height > gif->height)) { - return_value = GIF_DATA_ERROR; - goto gif_decode_frame_exit; - } - - /* Make sure we have a buffer to decode to. - */ - if (gif_initialise_sprite(gif, gif->width, gif->height)) { - return GIF_INSUFFICIENT_MEMORY; - } - - /* Decode the flags */ - flags = gif_data[9]; - colour_table_size = 2 << (flags & GIF_COLOUR_TABLE_SIZE_MASK); - interlace = flags & GIF_INTERLACE_MASK; - - /* Advance data pointer to next block either colour table or image - * data. - */ - gif_data += 10; - gif_bytes = (gif_end - gif_data); - - /* Set up the colour table */ - if (flags & GIF_COLOUR_TABLE_MASK) { - if (gif_bytes < (int)(3 * colour_table_size)) { - return_value = GIF_INSUFFICIENT_FRAME_DATA; - goto gif_decode_frame_exit; - } - colour_table = gif->local_colour_table; - if (!clear_image) { - for (index = 0; index < colour_table_size; index++) { - /* Gif colour map contents are r,g,b. - * - * We want to pack them bytewise into the - * colour table, such that the red component - * is in byte 0 and the alpha component is in - * byte 3. - */ - unsigned char *entry = - (unsigned char *) &colour_table[index]; - - entry[0] = gif_data[0]; /* r */ - entry[1] = gif_data[1]; /* g */ - entry[2] = gif_data[2]; /* b */ - entry[3] = 0xff; /* a */ - - gif_data += 3; - } - } else { - gif_data += 3 * colour_table_size; - } - gif_bytes = (gif_end - gif_data); - } else { - colour_table = gif->global_colour_table; - } - - /* Ensure sufficient data remains */ - if (gif_bytes < 1) { - return_value = GIF_INSUFFICIENT_FRAME_DATA; - goto gif_decode_frame_exit; - } - - /* check for an end marker */ - if (gif_data[0] == GIF_TRAILER) { - return_value = GIF_OK; - goto gif_decode_frame_exit; - } - - /* Get the frame data */ - assert(gif->bitmap_callbacks.bitmap_get_buffer); - frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image); - if (!frame_data) { - return GIF_INSUFFICIENT_MEMORY; - } - - /* If we are clearing the image we just clear, if not decode */ - if (!clear_image) { - /* Ensure we have enough data for a 1-byte LZW code size + - * 1-byte gif trailer - */ - if (gif_bytes < 2) { - return_value = GIF_INSUFFICIENT_FRAME_DATA; - goto gif_decode_frame_exit; - } - - /* If we only have a 1-byte LZW code size + 1-byte gif trailer, - * we're finished - */ - if ((gif_bytes == 2) && (gif_data[1] == GIF_TRAILER)) { - return_value = GIF_OK; - goto gif_decode_frame_exit; - } - - /* If the previous frame's disposal method requires we restore - * the background colour or this is the first frame, clear - * the frame data - */ - if ((frame == 0) || (gif->decoded_frame == GIF_INVALID_FRAME)) { - memset((char*)frame_data, - GIF_TRANSPARENT_COLOUR, - gif->width * gif->height * sizeof(int)); - gif->decoded_frame = frame; - /* The line below would fill the image with its - * background color, but because GIFs support - * transparency we likely wouldn't want to do that. */ - /* memset((char*)frame_data, colour_table[gif->background_index], gif->width * gif->height * sizeof(int)); */ - } else if ((frame != 0) && - (gif->frames[frame - 1].disposal_method == GIF_FRAME_CLEAR)) { - return_value = gif_internal_decode_frame(gif, - (frame - 1), - true); - if (return_value != GIF_OK) { - goto gif_decode_frame_exit; - } - - } else if ((frame != 0) && - (gif->frames[frame - 1].disposal_method == GIF_FRAME_RESTORE)) { - /* - * If the previous frame's disposal method requires we - * restore the previous image, restore our saved image. - */ - err = gif__recover_previous_frame(gif); - if (err != GIF_OK) { - /* see notes above on transparency - * vs. background color - */ - memset((char*)frame_data, - GIF_TRANSPARENT_COLOUR, - gif->width * gif->height * sizeof(int)); - } - } - - if (gif->frames[frame].disposal_method == GIF_FRAME_RESTORE) { - /* Store the previous frame for later restoration */ - gif__record_previous_frame(gif); - } - - gif->decoded_frame = frame; - gif->buffer_position = (gif_data - gif->gif_data) + 1; - - return_value = gif__decode(gif, frame, width, height, - offset_x, offset_y, interlace, gif_data[0], - frame_data, colour_table); - } else { - /* Clear our frame */ - if (gif->frames[frame].disposal_method == GIF_FRAME_CLEAR) { - unsigned int y; - for (y = 0; y < height; y++) { - unsigned int *frame_scanline; - frame_scanline = frame_data + offset_x + ((offset_y + y) * gif->width); - if (gif->frames[frame].transparency) { - memset(frame_scanline, - GIF_TRANSPARENT_COLOUR, - width * 4); - } else { - memset(frame_scanline, - colour_table[gif->background_index], - width * 4); - } - } - } - } + gif_result err; + unsigned int index = 0; + unsigned char *gif_data, *gif_end; + int gif_bytes; + unsigned int width, height, offset_x, offset_y; + unsigned int flags, colour_table_size, interlace; + unsigned int *colour_table; + unsigned int *frame_data = 0; // Set to 0 for no warnings + unsigned int save_buffer_position; + unsigned int return_value = 0; + + /* Ensure this frame is supposed to be decoded */ + if (gif->frames[frame].display == false) { + return GIF_OK; + } + + /* Ensure the frame is in range to decode */ + if (frame > gif->frame_count_partial) { + return GIF_INSUFFICIENT_DATA; + } + + /* done if frame is already decoded */ + if ((!clear_image) && + ((int)frame == gif->decoded_frame)) { + return GIF_OK; + } + + /* Get the start of our frame data and the end of the GIF data */ + gif_data = gif->gif_data + gif->frames[frame].frame_pointer; + gif_end = gif->gif_data + gif->buffer_size; + gif_bytes = (gif_end - gif_data); + + /* + * Ensure there is a minimal amount of data to proceed. The shortest + * block of data is a 10-byte image descriptor + 1-byte gif trailer + */ + if (gif_bytes < 12) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + + /* Save the buffer position */ + save_buffer_position = gif->buffer_position; + gif->buffer_position = gif_data - gif->gif_data; + + /* Skip any extensions because they have already been processed */ + if ((return_value = gif_skip_frame_extensions(gif)) != GIF_OK) { + goto gif_decode_frame_exit; + } + gif_data = (gif->gif_data + gif->buffer_position); + gif_bytes = (gif_end - gif_data); + + /* Ensure we have enough data for the 10-byte image descriptor + 1-byte + * gif trailer + */ + if (gif_bytes < 12) { + return_value = GIF_INSUFFICIENT_FRAME_DATA; + goto gif_decode_frame_exit; + } + + /* 10-byte Image Descriptor is: + * + * +0 CHAR Image Separator (0x2c) + * +1 SHORT Image Left Position + * +3 SHORT Image Top Position + * +5 SHORT Width + * +7 SHORT Height + * +9 CHAR __Packed Fields__ + * 1BIT Local Colour Table Flag + * 1BIT Interlace Flag + * 1BIT Sort Flag + * 2BITS Reserved + * 3BITS Size of Local Colour Table + */ + if (gif_data[0] != GIF_IMAGE_SEPARATOR) { + return_value = GIF_DATA_ERROR; + goto gif_decode_frame_exit; + } + offset_x = gif_data[1] | (gif_data[2] << 8); + offset_y = gif_data[3] | (gif_data[4] << 8); + width = gif_data[5] | (gif_data[6] << 8); + height = gif_data[7] | (gif_data[8] << 8); + + /* Boundary checking - shouldn't ever happen except unless the data has + * been modified since initialisation. + */ + if ((offset_x + width > gif->width) || + (offset_y + height > gif->height)) { + return_value = GIF_DATA_ERROR; + goto gif_decode_frame_exit; + } + + /* Make sure we have a buffer to decode to. + */ + if (gif_initialise_sprite(gif, gif->width, gif->height)) { + return GIF_INSUFFICIENT_MEMORY; + } + + /* Decode the flags */ + flags = gif_data[9]; + colour_table_size = 2 << (flags & GIF_COLOUR_TABLE_SIZE_MASK); + interlace = flags & GIF_INTERLACE_MASK; + + /* Advance data pointer to next block either colour table or image + * data. + */ + gif_data += 10; + gif_bytes = (gif_end - gif_data); + + /* Set up the colour table */ + if (flags & GIF_COLOUR_TABLE_MASK) { + if (gif_bytes < (int)(3 * colour_table_size)) { + return_value = GIF_INSUFFICIENT_FRAME_DATA; + goto gif_decode_frame_exit; + } + colour_table = gif->local_colour_table; + if (!clear_image) { + for (index = 0; index < colour_table_size; index++) { + /* Gif colour map contents are r,g,b. + * + * We want to pack them bytewise into the + * colour table, such that the red component + * is in byte 0 and the alpha component is in + * byte 3. + */ + unsigned char *entry = + (unsigned char *) &colour_table[index]; + + entry[0] = gif_data[0]; /* r */ + entry[1] = gif_data[1]; /* g */ + entry[2] = gif_data[2]; /* b */ + entry[3] = 0xff; /* a */ + + gif_data += 3; + } + } else { + gif_data += 3 * colour_table_size; + } + gif_bytes = (gif_end - gif_data); + } else { + colour_table = gif->global_colour_table; + } + + /* Ensure sufficient data remains */ + if (gif_bytes < 1) { + return_value = GIF_INSUFFICIENT_FRAME_DATA; + goto gif_decode_frame_exit; + } + + /* check for an end marker */ + if (gif_data[0] == GIF_TRAILER) { + return_value = GIF_OK; + goto gif_decode_frame_exit; + } + + /* Get the frame data */ + assert(gif->bitmap_callbacks.bitmap_get_buffer); + frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image); + if (!frame_data) { + return GIF_INSUFFICIENT_MEMORY; + } + + /* If we are clearing the image we just clear, if not decode */ + if (!clear_image) { + /* Ensure we have enough data for a 1-byte LZW code size + + * 1-byte gif trailer + */ + if (gif_bytes < 2) { + return_value = GIF_INSUFFICIENT_FRAME_DATA; + goto gif_decode_frame_exit; + } + + /* If we only have a 1-byte LZW code size + 1-byte gif trailer, + * we're finished + */ + if ((gif_bytes == 2) && (gif_data[1] == GIF_TRAILER)) { + return_value = GIF_OK; + goto gif_decode_frame_exit; + } + + /* If the previous frame's disposal method requires we restore + * the background colour or this is the first frame, clear + * the frame data + */ + if ((frame == 0) || (gif->decoded_frame == GIF_INVALID_FRAME)) { + memset((char*)frame_data, + GIF_TRANSPARENT_COLOUR, + gif->width * gif->height * sizeof(int)); + gif->decoded_frame = frame; + /* The line below would fill the image with its + * background color, but because GIFs support + * transparency we likely wouldn't want to do that. */ + /* memset((char*)frame_data, colour_table[gif->background_index], gif->width * gif->height * sizeof(int)); */ + } else if ((frame != 0) && + (gif->frames[frame - 1].disposal_method == GIF_FRAME_CLEAR)) { + return_value = gif_internal_decode_frame(gif, + (frame - 1), + true); + if (return_value != GIF_OK) { + goto gif_decode_frame_exit; + } + + } else if ((frame != 0) && + (gif->frames[frame - 1].disposal_method == GIF_FRAME_RESTORE)) { + /* + * If the previous frame's disposal method requires we + * restore the previous image, restore our saved image. + */ + err = gif__recover_previous_frame(gif); + if (err != GIF_OK) { + /* see notes above on transparency + * vs. background color + */ + memset((char*)frame_data, + GIF_TRANSPARENT_COLOUR, + gif->width * gif->height * sizeof(int)); + } + } + + if (gif->frames[frame].disposal_method == GIF_FRAME_RESTORE) { + /* Store the previous frame for later restoration */ + gif__record_previous_frame(gif); + } + + gif->decoded_frame = frame; + gif->buffer_position = (gif_data - gif->gif_data) + 1; + + return_value = gif__decode(gif, frame, width, height, + offset_x, offset_y, interlace, gif_data[0], + frame_data, colour_table); + } else { + /* Clear our frame */ + if (gif->frames[frame].disposal_method == GIF_FRAME_CLEAR) { + unsigned int y; + for (y = 0; y < height; y++) { + unsigned int *frame_scanline; + frame_scanline = frame_data + offset_x + ((offset_y + y) * gif->width); + if (gif->frames[frame].transparency) { + memset(frame_scanline, + GIF_TRANSPARENT_COLOUR, + width * 4); + } else { + memset(frame_scanline, + colour_table[gif->background_index], + width * 4); + } + } + } + } gif_decode_frame_exit: - /* Check if we should test for optimisation */ - if (gif->frames[frame].virgin) { - if (gif->bitmap_callbacks.bitmap_test_opaque) { - gif->frames[frame].opaque = gif->bitmap_callbacks.bitmap_test_opaque(gif->frame_image); - } else { - gif->frames[frame].opaque = false; - } - gif->frames[frame].virgin = false; - } + /* Check if we should test for optimisation */ + if (gif->frames[frame].virgin) { + if (gif->bitmap_callbacks.bitmap_test_opaque) { + gif->frames[frame].opaque = gif->bitmap_callbacks.bitmap_test_opaque(gif->frame_image); + } else { + gif->frames[frame].opaque = false; + } + gif->frames[frame].virgin = false; + } - if (gif->bitmap_callbacks.bitmap_set_opaque) { - gif->bitmap_callbacks.bitmap_set_opaque(gif->frame_image, gif->frames[frame].opaque); - } + if (gif->bitmap_callbacks.bitmap_set_opaque) { + gif->bitmap_callbacks.bitmap_set_opaque(gif->frame_image, gif->frames[frame].opaque); + } - if (gif->bitmap_callbacks.bitmap_modified) { - gif->bitmap_callbacks.bitmap_modified(gif->frame_image); - } + if (gif->bitmap_callbacks.bitmap_modified) { + gif->bitmap_callbacks.bitmap_modified(gif->frame_image); + } - /* Restore the buffer position */ - gif->buffer_position = save_buffer_position; + /* Restore the buffer position */ + gif->buffer_position = save_buffer_position; - return return_value; + return return_value; } /* exported function documented in libnsgif.h */ void gif_create(gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks) { - memset(gif, 0, sizeof(gif_animation)); - gif->bitmap_callbacks = *bitmap_callbacks; - gif->decoded_frame = GIF_INVALID_FRAME; - gif->prev_index = GIF_INVALID_FRAME; + memset(gif, 0, sizeof(gif_animation)); + gif->bitmap_callbacks = *bitmap_callbacks; + gif->decoded_frame = GIF_INVALID_FRAME; + gif->prev_index = GIF_INVALID_FRAME; } /* exported function documented in libnsgif.h */ gif_result gif_initialise(gif_animation *gif, size_t size, unsigned char *data) { - unsigned char *gif_data; - unsigned int index; - gif_result return_value; - - /* Initialize values */ - gif->buffer_size = size; - gif->gif_data = data; - - if (gif->lzw_ctx == NULL) { - lzw_result res = lzw_context_create( - (struct lzw_ctx **)&gif->lzw_ctx); - if (res != LZW_OK) { - return gif_error_from_lzw(res); - } - } - - /* Check for sufficient data to be a GIF (6-byte header + 7-byte - * logical screen descriptor) - */ - if (gif->buffer_size < GIF_STANDARD_HEADER_SIZE) { - return GIF_INSUFFICIENT_DATA; - } - - /* Get our current processing position */ - gif_data = gif->gif_data + gif->buffer_position; - - /* See if we should initialise the GIF */ - if (gif->buffer_position == 0) { - /* We want everything to be NULL before we start so we've no - * chance of freeing bad pointers (paranoia) - */ - gif->frame_image = NULL; - gif->frames = NULL; - gif->local_colour_table = NULL; - gif->global_colour_table = NULL; - - /* The caller may have been lazy and not reset any values */ - gif->frame_count = 0; - gif->frame_count_partial = 0; - gif->decoded_frame = GIF_INVALID_FRAME; - - /* 6-byte GIF file header is: - * - * +0 3CHARS Signature ('GIF') - * +3 3CHARS Version ('87a' or '89a') - */ - if (strncmp((const char *) gif_data, "GIF", 3) != 0) { - return GIF_DATA_ERROR; - } - gif_data += 3; - - /* Ensure GIF reports version 87a or 89a */ - /* - if ((strncmp(gif_data, "87a", 3) != 0) && - (strncmp(gif_data, "89a", 3) != 0)) - LOG(("Unknown GIF format - proceeding anyway")); - */ - gif_data += 3; - - /* 7-byte Logical Screen Descriptor is: - * - * +0 SHORT Logical Screen Width - * +2 SHORT Logical Screen Height - * +4 CHAR __Packed Fields__ - * 1BIT Global Colour Table Flag - * 3BITS Colour Resolution - * 1BIT Sort Flag - * 3BITS Size of Global Colour Table - * +5 CHAR Background Colour Index - * +6 CHAR Pixel Aspect Ratio - */ - gif->width = gif_data[0] | (gif_data[1] << 8); - gif->height = gif_data[2] | (gif_data[3] << 8); - gif->global_colours = (gif_data[4] & GIF_COLOUR_TABLE_MASK); - gif->colour_table_size = (2 << (gif_data[4] & GIF_COLOUR_TABLE_SIZE_MASK)); - gif->background_index = gif_data[5]; - gif->aspect_ratio = gif_data[6]; - gif->loop_count = 1; - gif_data += 7; - - /* Some broken GIFs report the size as the screen size they - * were created in. As such, we detect for the common cases and - * set the sizes as 0 if they are found which results in the - * GIF being the maximum size of the frames. - */ - if (((gif->width == 640) && (gif->height == 480)) || - ((gif->width == 640) && (gif->height == 512)) || - ((gif->width == 800) && (gif->height == 600)) || - ((gif->width == 1024) && (gif->height == 768)) || - ((gif->width == 1280) && (gif->height == 1024)) || - ((gif->width == 1600) && (gif->height == 1200)) || - ((gif->width == 0) || (gif->height == 0)) || - ((gif->width > 2048) || (gif->height > 2048))) { - gif->width = 1; - gif->height = 1; - } - - /* Allocate some data irrespective of whether we've got any - * colour tables. We always get the maximum size in case a GIF - * is lying to us. It's far better to give the wrong colours - * than to trample over some memory somewhere. - */ - gif->global_colour_table = calloc(GIF_MAX_COLOURS, sizeof(unsigned int)); - gif->local_colour_table = calloc(GIF_MAX_COLOURS, sizeof(unsigned int)); - if ((gif->global_colour_table == NULL) || - (gif->local_colour_table == NULL)) { - gif_finalise(gif); - return GIF_INSUFFICIENT_MEMORY; - } - - /* Set the first colour to a value that will never occur in - * reality so we know if we've processed it - */ - gif->global_colour_table[0] = GIF_PROCESS_COLOURS; - - /* Check if the GIF has no frame data (13-byte header + 1-byte - * termination block) Although generally useless, the GIF - * specification does not expressly prohibit this - */ - if (gif->buffer_size == (GIF_STANDARD_HEADER_SIZE + 1)) { - if (gif_data[0] == GIF_TRAILER) { - return GIF_OK; - } else { - return GIF_INSUFFICIENT_DATA; - } - } - - /* Initialise enough workspace for a frame */ - if ((gif->frames = (gif_frame *)malloc(sizeof(gif_frame))) == NULL) { - gif_finalise(gif); - return GIF_INSUFFICIENT_MEMORY; - } - gif->frame_holders = 1; - - /* Remember we've done this now */ - gif->buffer_position = gif_data - gif->gif_data; - } - - /* Do the colour map if we haven't already. As the top byte is always - * 0xff or 0x00 depending on the transparency we know if it's been - * filled in. - */ - if (gif->global_colour_table[0] == GIF_PROCESS_COLOURS) { - /* Check for a global colour map signified by bit 7 */ - if (gif->global_colours) { - if (gif->buffer_size < (gif->colour_table_size * 3 + GIF_STANDARD_HEADER_SIZE)) { - return GIF_INSUFFICIENT_DATA; - } - for (index = 0; index < gif->colour_table_size; index++) { - /* Gif colour map contents are r,g,b. - * - * We want to pack them bytewise into the - * colour table, such that the red component - * is in byte 0 and the alpha component is in - * byte 3. - */ - unsigned char *entry = (unsigned char *) &gif-> - global_colour_table[index]; - - entry[0] = gif_data[0]; /* r */ - entry[1] = gif_data[1]; /* g */ - entry[2] = gif_data[2]; /* b */ - entry[3] = 0xff; /* a */ - - gif_data += 3; - } - gif->buffer_position = (gif_data - gif->gif_data); - } else { - /* Create a default colour table with the first two - * colours as black and white - */ - unsigned int *entry = gif->global_colour_table; - - entry[0] = 0x00000000; - /* Force Alpha channel to opaque */ - ((unsigned char *) entry)[3] = 0xff; - - entry[1] = 0xffffffff; - } - } - - /* Repeatedly try to initialise frames */ - while ((return_value = gif_initialise_frame(gif)) == GIF_WORKING); - - /* If there was a memory error tell the caller */ - if ((return_value == GIF_INSUFFICIENT_MEMORY) || - (return_value == GIF_DATA_ERROR)) { - return return_value; - } - - /* If we didn't have some frames then a GIF_INSUFFICIENT_DATA becomes a - * GIF_INSUFFICIENT_FRAME_DATA - */ - if ((return_value == GIF_INSUFFICIENT_DATA) && - (gif->frame_count_partial > 0)) { - return GIF_INSUFFICIENT_FRAME_DATA; - } - - /* Return how many we got */ - return return_value; + unsigned char *gif_data; + unsigned int index; + gif_result return_value; + + /* Initialize values */ + gif->buffer_size = size; + gif->gif_data = data; + + if (gif->lzw_ctx == NULL) { + lzw_result res = lzw_context_create( + (struct lzw_ctx **)&gif->lzw_ctx); + if (res != LZW_OK) { + return gif_error_from_lzw(res); + } + } + + /* Check for sufficient data to be a GIF (6-byte header + 7-byte + * logical screen descriptor) + */ + if (gif->buffer_size < GIF_STANDARD_HEADER_SIZE) { + return GIF_INSUFFICIENT_DATA; + } + + /* Get our current processing position */ + gif_data = gif->gif_data + gif->buffer_position; + + /* See if we should initialise the GIF */ + if (gif->buffer_position == 0) { + /* We want everything to be NULL before we start so we've no + * chance of freeing bad pointers (paranoia) + */ + gif->frame_image = NULL; + gif->frames = NULL; + gif->local_colour_table = NULL; + gif->global_colour_table = NULL; + + /* The caller may have been lazy and not reset any values */ + gif->frame_count = 0; + gif->frame_count_partial = 0; + gif->decoded_frame = GIF_INVALID_FRAME; + + /* 6-byte GIF file header is: + * + * +0 3CHARS Signature ('GIF') + * +3 3CHARS Version ('87a' or '89a') + */ + if (strncmp((const char *) gif_data, "GIF", 3) != 0) { + return GIF_DATA_ERROR; + } + gif_data += 3; + + /* Ensure GIF reports version 87a or 89a */ + /* + if ((strncmp(gif_data, "87a", 3) != 0) && + (strncmp(gif_data, "89a", 3) != 0)) + LOG(("Unknown GIF format - proceeding anyway")); + */ + gif_data += 3; + + /* 7-byte Logical Screen Descriptor is: + * + * +0 SHORT Logical Screen Width + * +2 SHORT Logical Screen Height + * +4 CHAR __Packed Fields__ + * 1BIT Global Colour Table Flag + * 3BITS Colour Resolution + * 1BIT Sort Flag + * 3BITS Size of Global Colour Table + * +5 CHAR Background Colour Index + * +6 CHAR Pixel Aspect Ratio + */ + gif->width = gif_data[0] | (gif_data[1] << 8); + gif->height = gif_data[2] | (gif_data[3] << 8); + gif->global_colours = (gif_data[4] & GIF_COLOUR_TABLE_MASK); + gif->colour_table_size = (2 << (gif_data[4] & GIF_COLOUR_TABLE_SIZE_MASK)); + gif->background_index = gif_data[5]; + gif->aspect_ratio = gif_data[6]; + gif->loop_count = 1; + gif_data += 7; + + /* Some broken GIFs report the size as the screen size they + * were created in. As such, we detect for the common cases and + * set the sizes as 0 if they are found which results in the + * GIF being the maximum size of the frames. + */ + if (((gif->width == 640) && (gif->height == 480)) || + ((gif->width == 640) && (gif->height == 512)) || + ((gif->width == 800) && (gif->height == 600)) || + ((gif->width == 1024) && (gif->height == 768)) || + ((gif->width == 1280) && (gif->height == 1024)) || + ((gif->width == 1600) && (gif->height == 1200)) || + ((gif->width == 0) || (gif->height == 0)) || + ((gif->width > 2048) || (gif->height > 2048))) { + gif->width = 1; + gif->height = 1; + } + + /* Allocate some data irrespective of whether we've got any + * colour tables. We always get the maximum size in case a GIF + * is lying to us. It's far better to give the wrong colours + * than to trample over some memory somewhere. + */ + gif->global_colour_table = calloc(GIF_MAX_COLOURS, sizeof(unsigned int)); + gif->local_colour_table = calloc(GIF_MAX_COLOURS, sizeof(unsigned int)); + if ((gif->global_colour_table == NULL) || + (gif->local_colour_table == NULL)) { + gif_finalise(gif); + return GIF_INSUFFICIENT_MEMORY; + } + + /* Set the first colour to a value that will never occur in + * reality so we know if we've processed it + */ + gif->global_colour_table[0] = GIF_PROCESS_COLOURS; + + /* Check if the GIF has no frame data (13-byte header + 1-byte + * termination block) Although generally useless, the GIF + * specification does not expressly prohibit this + */ + if (gif->buffer_size == (GIF_STANDARD_HEADER_SIZE + 1)) { + if (gif_data[0] == GIF_TRAILER) { + return GIF_OK; + } else { + return GIF_INSUFFICIENT_DATA; + } + } + + /* Initialise enough workspace for a frame */ + if ((gif->frames = (gif_frame *)malloc(sizeof(gif_frame))) == NULL) { + gif_finalise(gif); + return GIF_INSUFFICIENT_MEMORY; + } + gif->frame_holders = 1; + + /* Remember we've done this now */ + gif->buffer_position = gif_data - gif->gif_data; + } + + /* Do the colour map if we haven't already. As the top byte is always + * 0xff or 0x00 depending on the transparency we know if it's been + * filled in. + */ + if (gif->global_colour_table[0] == GIF_PROCESS_COLOURS) { + /* Check for a global colour map signified by bit 7 */ + if (gif->global_colours) { + if (gif->buffer_size < (gif->colour_table_size * 3 + GIF_STANDARD_HEADER_SIZE)) { + return GIF_INSUFFICIENT_DATA; + } + for (index = 0; index < gif->colour_table_size; index++) { + /* Gif colour map contents are r,g,b. + * + * We want to pack them bytewise into the + * colour table, such that the red component + * is in byte 0 and the alpha component is in + * byte 3. + */ + unsigned char *entry = (unsigned char *) &gif-> + global_colour_table[index]; + + entry[0] = gif_data[0]; /* r */ + entry[1] = gif_data[1]; /* g */ + entry[2] = gif_data[2]; /* b */ + entry[3] = 0xff; /* a */ + + gif_data += 3; + } + gif->buffer_position = (gif_data - gif->gif_data); + } else { + /* Create a default colour table with the first two + * colours as black and white + */ + unsigned int *entry = gif->global_colour_table; + + entry[0] = 0x00000000; + /* Force Alpha channel to opaque */ + ((unsigned char *) entry)[3] = 0xff; + + entry[1] = 0xffffffff; + } + } + + /* Repeatedly try to initialise frames */ + while ((return_value = gif_initialise_frame(gif)) == GIF_WORKING); + + /* If there was a memory error tell the caller */ + if ((return_value == GIF_INSUFFICIENT_MEMORY) || + (return_value == GIF_DATA_ERROR)) { + return return_value; + } + + /* If we didn't have some frames then a GIF_INSUFFICIENT_DATA becomes a + * GIF_INSUFFICIENT_FRAME_DATA + */ + if ((return_value == GIF_INSUFFICIENT_DATA) && + (gif->frame_count_partial > 0)) { + return GIF_INSUFFICIENT_FRAME_DATA; + } + + /* Return how many we got */ + return return_value; } /* exported function documented in libnsgif.h */ gif_result gif_decode_frame(gif_animation *gif, unsigned int frame) { - return gif_internal_decode_frame(gif, frame, false); + return gif_internal_decode_frame(gif, frame, false); } /* exported function documented in libnsgif.h */ void gif_finalise(gif_animation *gif) { - /* Release all our memory blocks */ - if (gif->frame_image) { - assert(gif->bitmap_callbacks.bitmap_destroy); - gif->bitmap_callbacks.bitmap_destroy(gif->frame_image); - } - - gif->frame_image = NULL; - free(gif->frames); - gif->frames = NULL; - free(gif->local_colour_table); - gif->local_colour_table = NULL; - free(gif->global_colour_table); - gif->global_colour_table = NULL; - - free(gif->prev_frame); - gif->prev_frame = NULL; - - lzw_context_destroy(gif->lzw_ctx); - gif->lzw_ctx = NULL; + /* Release all our memory blocks */ + if (gif->frame_image) { + assert(gif->bitmap_callbacks.bitmap_destroy); + gif->bitmap_callbacks.bitmap_destroy(gif->frame_image); + } + + gif->frame_image = NULL; + free(gif->frames); + gif->frames = NULL; + free(gif->local_colour_table); + gif->local_colour_table = NULL; + free(gif->global_colour_table); + gif->global_colour_table = NULL; + + free(gif->prev_frame); + gif->prev_frame = NULL; + + lzw_context_destroy(gif->lzw_ctx); + gif->lzw_ctx = NULL; } |