diff options
| -rwxr-xr-x[-rw-r--r--] | libavcodec/gifdec.c | 285 | ||||
| -rw-r--r-- | libavcodec/version.h | 4 |
2 files changed, 240 insertions, 49 deletions
diff --git a/libavcodec/gifdec.c b/libavcodec/gifdec.c index 91139e195b..887a253599 100644..100755 --- a/libavcodec/gifdec.c +++ b/libavcodec/gifdec.c @@ -2,6 +2,7 @@ * GIF decoder * Copyright (c) 2003 Fabrice Bellard * Copyright (c) 2006 Baptiste Coudurier + * Copyright (c) 2012 Vitaliy E Sugrobov * * This file is part of FFmpeg. * @@ -23,6 +24,7 @@ //#define DEBUG #include "libavutil/imgutils.h" +#include "libavutil/opt.h" #include "avcodec.h" #include "bytestream.h" #include "lzw.h" @@ -35,21 +37,37 @@ #define GIF_EXTENSION_INTRODUCER 0x21 #define GIF_IMAGE_SEPARATOR 0x2c #define GIF_GCE_EXT_LABEL 0xf9 +/* This value is intentionally set to "transparent white" color. + * It is much better to have white background instead of black + * when gif image converted to format which not support transparency. + */ +#define GIF_TRANSPARENT_COLOR 0x00ffffff typedef struct GifState { + const AVClass *class; AVFrame picture; int screen_width; int screen_height; + int has_global_palette; int bits_per_pixel; + uint32_t bg_color; int background_color_index; int transparent_color_index; int color_resolution; - uint32_t *image_palette; + /* intermediate buffer for storing color indices + * obtained from lzw-encoded data stream */ + uint8_t *idx_line; /* after the frame is displayed, the disposal method is used */ + int gce_prev_disposal; int gce_disposal; - /* delay during which the frame is shown */ - int gce_delay; + /* rectangle describing area that must be disposed */ + int gce_l, gce_t, gce_w, gce_h; + /* depending on disposal method we store either part of the image + * drawn on the canvas or background color that + * should be used upon disposal */ + uint32_t * stored_img; + int stored_bg_color; /* LZW compatible decoder */ const uint8_t *bytestream; @@ -57,21 +75,76 @@ typedef struct GifState { LZWState *lzw; /* aux buffers */ - uint8_t global_palette[256 * 3]; - uint8_t local_palette[256 * 3]; + uint32_t global_palette[256]; + uint32_t local_palette[256]; AVCodecContext *avctx; + int keyframe; + int trans_color; /**< color value that is used instead of transparent color */ } GifState; static const uint8_t gif87a_sig[6] = "GIF87a"; static const uint8_t gif89a_sig[6] = "GIF89a"; +static void gif_read_palette(const uint8_t **buf, uint32_t *pal, int nb) +{ + const uint8_t *pal_end = *buf + nb * 3; + + for (; *buf < pal_end; *buf += 3, pal++) + *pal = (0xffu << 24) | AV_RB24(*buf); +} + +static void gif_fill(AVFrame *picture, uint32_t color) +{ + uint32_t *p = (uint32_t *)picture->data[0]; + uint32_t *p_end = p + (picture->linesize[0] / sizeof(uint32_t)) * picture->height; + + for (; p < p_end; p++) + *p = color; +} + +static void gif_fill_rect(AVFrame *picture, uint32_t color, int l, int t, int w, int h) +{ + const int linesize = picture->linesize[0] / sizeof(uint32_t); + const uint32_t *py = (uint32_t *)picture->data[0] + t * linesize; + const uint32_t *pr, *pb = py + (t + h) * linesize; + uint32_t *px; + + for (; py < pb; py += linesize) { + px = (uint32_t *)py + l; + pr = px + w; + + for (; px < pr; px++) + *px = color; + } +} + +static void gif_copy_img_rect(const uint32_t *src, uint32_t *dst, + int linesize, int l, int t, int w, int h) +{ + const int y_start = t * linesize; + const uint32_t *src_px, *src_pr, + *src_py = src + y_start, + *dst_py = dst + y_start; + const uint32_t *src_pb = src_py + (t + h) * linesize; + uint32_t *dst_px; + + for (; src_py < src_pb; src_py += linesize, dst_py += linesize) { + src_px = src_py + l; + dst_px = (uint32_t *)dst_py + l; + src_pr = src_px + w; + + for (; src_px < src_pr; src_px++, dst_px++) + *dst_px = *src_px; + } +} static int gif_read_image(GifState *s) { int left, top, width, height, bits_per_pixel, code_size, flags; - int is_interleaved, has_local_palette, y, pass, y1, linesize, n, i; - uint8_t *ptr, *spal, *palette, *ptr1; + int is_interleaved, has_local_palette, y, pass, y1, linesize, pal_size; + uint32_t *ptr, *pal, *px, *pr, *ptr1; int ret; + uint8_t *idx; left = bytestream_get_le16(&s->bytestream); top = bytestream_get_le16(&s->bytestream); @@ -85,11 +158,31 @@ static int gif_read_image(GifState *s) av_dlog(s->avctx, "image x=%d y=%d w=%d h=%d\n", left, top, width, height); if (has_local_palette) { - bytestream_get_buffer(&s->bytestream, s->local_palette, 3 * (1 << bits_per_pixel)); - palette = s->local_palette; + pal_size = 1 << bits_per_pixel; + + if (s->bytestream_end < s->bytestream + pal_size * 3) + return AVERROR_INVALIDDATA; + + gif_read_palette(&s->bytestream, s->local_palette, pal_size); + pal = s->local_palette; } else { - palette = s->global_palette; - bits_per_pixel = s->bits_per_pixel; + if (!s->has_global_palette) { + av_log(s->avctx, AV_LOG_FATAL, "picture doesn't have either global or local palette.\n"); + return AVERROR_INVALIDDATA; + } + + pal = s->global_palette; + } + + if (s->keyframe) { + if (s->transparent_color_index == -1 && s->has_global_palette) { + /* transparency wasn't set before the first frame, fill with background color */ + gif_fill(&s->picture, s->bg_color); + } else { + /* otherwise fill with transparent color. + * this is necessary since by default picture filled with 0x80808080. */ + gif_fill(&s->picture, s->trans_color); + } } /* verify that all the image is inside the screen dimensions */ @@ -97,18 +190,37 @@ static int gif_read_image(GifState *s) top + height > s->screen_height) return AVERROR(EINVAL); - /* build the palette */ - n = (1 << bits_per_pixel); - spal = palette; - for(i = 0; i < n; i++) { - s->image_palette[i] = (0xffu << 24) | AV_RB24(spal); - spal += 3; + /* process disposal method */ + if (s->gce_prev_disposal == GCE_DISPOSAL_BACKGROUND) { + gif_fill_rect(&s->picture, s->stored_bg_color, s->gce_l, s->gce_t, s->gce_w, s->gce_h); + } else if (s->gce_prev_disposal == GCE_DISPOSAL_RESTORE) { + gif_copy_img_rect(s->stored_img, (uint32_t *)s->picture.data[0], + s->picture.linesize[0] / sizeof(uint32_t), s->gce_l, s->gce_t, s->gce_w, s->gce_h); + } + + s->gce_prev_disposal = s->gce_disposal; + + if (s->gce_disposal != GCE_DISPOSAL_NONE) { + s->gce_l = left; s->gce_t = top; + s->gce_w = width; s->gce_h = height; + + if (s->gce_disposal == GCE_DISPOSAL_BACKGROUND) { + if (s->background_color_index == s->transparent_color_index) + s->stored_bg_color = s->trans_color; + else + s->stored_bg_color = s->bg_color; + } else if (s->gce_disposal == GCE_DISPOSAL_RESTORE) { + if (!s->stored_img) { + s->stored_img = av_malloc(s->picture.linesize[0] * s->picture.height); + + if (!s->stored_img) + return AVERROR(ENOMEM); + } + + gif_copy_img_rect((uint32_t *)s->picture.data[0], s->stored_img, + s->picture.linesize[0] / sizeof(uint32_t), left, top, width, height); + } } - for(; i < 256; i++) - s->image_palette[i] = (0xffu << 24); - /* handle transparency */ - if (s->transparent_color_index >= 0) - s->image_palette[s->transparent_color_index] = 0; /* now get the image data */ code_size = bytestream_get_byte(&s->bytestream); @@ -119,13 +231,22 @@ static int gif_read_image(GifState *s) } /* read all the image */ - linesize = s->picture.linesize[0]; - ptr1 = s->picture.data[0] + top * linesize + left; + linesize = s->picture.linesize[0] / sizeof(uint32_t); + ptr1 = (uint32_t *)s->picture.data[0] + top * linesize + left; ptr = ptr1; pass = 0; y1 = 0; for (y = 0; y < height; y++) { - ff_lzw_decode(s->lzw, ptr, width); + if (ff_lzw_decode(s->lzw, s->idx_line, width) == 0) + goto decode_tail; + + pr = ptr + width; + + for (px = ptr, idx = s->idx_line; px < pr; px++, idx++) { + if (*idx != s->transparent_color_index) + *px = pal[*idx]; + } + if (is_interleaved) { switch(pass) { default: @@ -157,9 +278,17 @@ static int gif_read_image(GifState *s) ptr += linesize; } } + + decode_tail: /* read the garbage data until end marker is found */ ff_lzw_decode_tail(s->lzw); s->bytestream = ff_lzw_cur_ptr(s->lzw); + + /* Graphic Control Extension's scope is single frame. + * Remove its influence. */ + s->transparent_color_index = -1; + s->gce_disposal = GCE_DISPOSAL_NONE; + return 0; } @@ -179,7 +308,7 @@ static int gif_read_extension(GifState *s) goto discard_ext; s->transparent_color_index = -1; gce_flags = bytestream_get_byte(&s->bytestream); - s->gce_delay = bytestream_get_le16(&s->bytestream); + bytestream_get_le16(&s->bytestream); // delay during which the frame is shown gce_transparent_index = bytestream_get_byte(&s->bytestream); if (gce_flags & 0x01) s->transparent_color_index = gce_transparent_index; @@ -187,10 +316,15 @@ static int gif_read_extension(GifState *s) s->transparent_color_index = -1; s->gce_disposal = (gce_flags >> 2) & 0x7; - av_dlog(s->avctx, "gce_flags=%x delay=%d tcolor=%d disposal=%d\n", - gce_flags, s->gce_delay, + av_dlog(s->avctx, "gce_flags=%x tcolor=%d disposal=%d\n", + gce_flags, s->transparent_color_index, s->gce_disposal); + if (s->gce_disposal > 3) { + s->gce_disposal = GCE_DISPOSAL_NONE; + av_dlog(s->avctx, "invalid value in gce_disposal (%d). Using default value of 0.\n", ext_len); + } + ext_len = bytestream_get_byte(&s->bytestream); break; } @@ -211,7 +345,7 @@ static int gif_read_header1(GifState *s) { uint8_t sig[6]; int v, n; - int has_global_palette; + int background_color_index; if (s->bytestream_end < s->bytestream + 13) return AVERROR_INVALIDDATA; @@ -232,23 +366,32 @@ static int gif_read_header1(GifState *s) return AVERROR_INVALIDDATA; } + s->idx_line = av_malloc(s->screen_width); + if (!s->idx_line) + return AVERROR(ENOMEM); + v = bytestream_get_byte(&s->bytestream); s->color_resolution = ((v & 0x70) >> 4) + 1; - has_global_palette = (v & 0x80); + s->has_global_palette = (v & 0x80); s->bits_per_pixel = (v & 0x07) + 1; - s->background_color_index = bytestream_get_byte(&s->bytestream); + background_color_index = bytestream_get_byte(&s->bytestream); bytestream_get_byte(&s->bytestream); /* ignored */ av_dlog(s->avctx, "screen_w=%d screen_h=%d bpp=%d global_palette=%d\n", s->screen_width, s->screen_height, s->bits_per_pixel, - has_global_palette); + s->has_global_palette); - if (has_global_palette) { + if (s->has_global_palette) { + s->background_color_index = background_color_index; n = 1 << s->bits_per_pixel; if (s->bytestream_end < s->bytestream + n * 3) return AVERROR_INVALIDDATA; - bytestream_get_buffer(&s->bytestream, s->global_palette, n * 3); - } + + gif_read_palette(&s->bytestream, s->global_palette, n); + s->bg_color = s->global_palette[s->background_color_index]; + } else + s->background_color_index = -1; + return 0; } @@ -286,6 +429,7 @@ static av_cold int gif_decode_init(AVCodecContext *avctx) s->avctx = avctx; + avctx->pix_fmt = AV_PIX_FMT_RGB32; avcodec_get_frame_defaults(&s->picture); avctx->coded_frame= &s->picture; s->picture.data[0] = NULL; @@ -301,23 +445,49 @@ static int gif_decode_frame(AVCodecContext *avctx, void *data, int *got_picture, AVFrame *picture = data; int ret; + s->picture.pts = avpkt->pts; + s->picture.pkt_pts = avpkt->pts; + s->picture.pkt_dts = avpkt->dts; + s->picture.pkt_duration = avpkt->duration; + s->bytestream = buf; s->bytestream_end = buf + buf_size; - if ((ret = gif_read_header1(s)) < 0) - return ret; - avctx->pix_fmt = AV_PIX_FMT_PAL8; - if ((ret = av_image_check_size(s->screen_width, s->screen_height, 0, avctx)) < 0) - return ret; - avcodec_set_dimensions(avctx, s->screen_width, s->screen_height); + if (buf_size >= 6) { + s->keyframe = memcmp(s->bytestream, gif87a_sig, 6) == 0 || + memcmp(s->bytestream, gif89a_sig, 6) == 0; + } else { + s->keyframe = 0; + } - if (s->picture.data[0]) - avctx->release_buffer(avctx, &s->picture); - if ((ret = avctx->get_buffer(avctx, &s->picture)) < 0) { - av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); - return ret; + if (s->keyframe) { + if ((ret = gif_read_header1(s)) < 0) + return ret; + + if ((ret = av_image_check_size(s->screen_width, s->screen_height, 0, avctx)) < 0) + return ret; + avcodec_set_dimensions(avctx, s->screen_width, s->screen_height); + + if (s->picture.data[0]) + avctx->release_buffer(avctx, &s->picture); + + if ((ret = avctx->get_buffer(avctx, &s->picture)) < 0) { + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); + return ret; + } + + s->picture.pict_type = AV_PICTURE_TYPE_I; + s->picture.key_frame = 1; + } else { + if ((ret = avctx->reget_buffer(avctx, &s->picture)) < 0) { + av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); + return ret; + } + + s->picture.pict_type = AV_PICTURE_TYPE_P; + s->picture.key_frame = 0; } - s->image_palette = (uint32_t *)s->picture.data[1]; + ret = gif_parse_next_image(s, got_picture); if (ret < 0) return ret; @@ -334,9 +504,29 @@ static av_cold int gif_decode_close(AVCodecContext *avctx) ff_lzw_decode_close(&s->lzw); if(s->picture.data[0]) avctx->release_buffer(avctx, &s->picture); + + av_freep(&s->idx_line); + av_freep(&s->stored_img); + return 0; } +static const AVOption options[] = { + { "trans_color", "color value (ARGB) that is used instead of transparent color", + offsetof(GifState, trans_color), AV_OPT_TYPE_INT, + {.i64 = GIF_TRANSPARENT_COLOR}, 0, 0xffffffff, + AV_OPT_FLAG_DECODING_PARAM|AV_OPT_FLAG_VIDEO_PARAM }, + { NULL }, +}; + +static const AVClass decoder_class = { + .class_name = "gif decoder", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, + .category = AV_CLASS_CATEGORY_DECODER, +}; + AVCodec ff_gif_decoder = { .name = "gif", .type = AVMEDIA_TYPE_VIDEO, @@ -347,4 +537,5 @@ AVCodec ff_gif_decoder = { .decode = gif_decode_frame, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"), + .priv_class = &decoder_class, }; diff --git a/libavcodec/version.h b/libavcodec/version.h index 197e8e3603..2148c4fe54 100644 --- a/libavcodec/version.h +++ b/libavcodec/version.h @@ -29,8 +29,8 @@ #include "libavutil/avutil.h" #define LIBAVCODEC_VERSION_MAJOR 54 -#define LIBAVCODEC_VERSION_MINOR 77 -#define LIBAVCODEC_VERSION_MICRO 101 +#define LIBAVCODEC_VERSION_MINOR 78 +#define LIBAVCODEC_VERSION_MICRO 100 #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \ LIBAVCODEC_VERSION_MINOR, \ |