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author | Fabrice Bellard <fabrice@bellard.org> | 2003-02-03 22:51:48 +0000 |
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committer | Fabrice Bellard <fabrice@bellard.org> | 2003-02-03 22:51:48 +0000 |
commit | fcfa89e81ca4fa8ce6c634221980490d4104aaf5 (patch) | |
tree | 4bbd44f320a091441dd538df99564a6a9fa55b0b /libavformat/gifdec.c | |
parent | b2609d4cbd1f0b90262b5c8fbf2e8d37d8a7cfd2 (diff) | |
download | ffmpeg-streaming-fcfa89e81ca4fa8ce6c634221980490d4104aaf5.zip ffmpeg-streaming-fcfa89e81ca4fa8ce6c634221980490d4104aaf5.tar.gz |
added automatic GIF/animated GIF probing - added GIF as an image format too - added interlaced gif support
Originally committed as revision 1539 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavformat/gifdec.c')
-rw-r--r-- | libavformat/gifdec.c | 252 |
1 files changed, 189 insertions, 63 deletions
diff --git a/libavformat/gifdec.c b/libavformat/gifdec.c index 63eb340..181d42a 100644 --- a/libavformat/gifdec.c +++ b/libavformat/gifdec.c @@ -18,6 +18,8 @@ */ #include "avformat.h" +int gif_write(ByteIOContext *pb, AVImageInfo *info); + //#define DEBUG #define MAXBITS 12 @@ -35,8 +37,8 @@ typedef struct GifState { int background_color_index; int transparent_color_index; int color_resolution; - int image_count; uint8_t *image_buf; + int image_linesize; /* after the frame is displayed, the disposal method is used */ int gce_disposal; /* delay during which the frame is shown */ @@ -81,16 +83,60 @@ static const uint16_t mask[17] = 0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF }; -static int gif_probe(AVProbeData * pd) +/* Probe gif video format or gif image format. The current heuristic + supposes the gif87a is always a single image. For gif89a, we + consider it as a video only if a GCE extension is present in the + first kilobyte. */ +static int gif_video_probe(AVProbeData * pd) +{ + const uint8_t *p, *p_end; + int bits_per_pixel, has_global_palette, ext_code, ext_len; + + if (pd->buf_size < 24 || + memcmp(pd->buf, gif89a_sig, 6) != 0) + return 0; + p_end = pd->buf + pd->buf_size; + p = pd->buf + 6; + bits_per_pixel = (p[4] & 0x07) + 1; + has_global_palette = (p[4] & 0x80); + p += 7; + if (has_global_palette) + p += (1 << bits_per_pixel) * 3; + for(;;) { + if (p >= p_end) + return 0; + if (*p != '!') + break; + p++; + if (p >= p_end) + return 0; + ext_code = *p++; + /* if GCE extension found: it is likely to be an animation */ + if (ext_code == 0xf9) + return AVPROBE_SCORE_MAX; + for(;;) { + if (p >= p_end) + return 0; + ext_len = *p++; + if (ext_len == 0) + break; + p += ext_len; + } + } + return 0; +} + +static int gif_image_probe(AVProbeData * pd) { if (pd->buf_size >= 24 && (memcmp(pd->buf, gif87a_sig, 6) == 0 || memcmp(pd->buf, gif89a_sig, 6) == 0)) - return AVPROBE_SCORE_MAX; + return AVPROBE_SCORE_MAX - 1; else return 0; } + static void GLZWDecodeInit(GifState * s, int csize) { /* read buffer */ @@ -224,13 +270,12 @@ static int GLZWDecode(GifState * s, uint8_t * buf, int len) return len - l; } -static int gif_read_image(AVFormatContext * s1, AVPacket * pkt) +static int gif_read_image(GifState *s) { - GifState *s = s1->priv_data; + ByteIOContext *f = s->f; int left, top, width, height, bits_per_pixel, code_size, flags; - int is_interleaved, has_local_palette, y, x, linesize; - ByteIOContext *f = &s1->pb; - uint8_t *ptr, *line, *d, *spal, *palette, *sptr; + int is_interleaved, has_local_palette, y, x, pass, y1, linesize; + uint8_t *ptr, *line, *d, *spal, *palette, *sptr, *ptr1; left = get_le16(f); top = get_le16(f); @@ -251,23 +296,10 @@ static int gif_read_image(AVFormatContext * s1, AVPacket * pkt) palette = s->global_palette; } - /* allocate local image (XXX: horrible, needs API change) */ - if (s->image_count == 0) { - /* modify screen width/height if invalid */ - if (left + width > s->screen_width) - s->screen_width = left + width; - if (top + height > s->screen_height) - s->screen_width = top + height; - s->image_buf = av_malloc(s->screen_width * s->screen_height * 3); - if (!s->image_buf) - return -ENOMEM; - } else { - /* verify that all the image is inside the screen dimensions */ - if (left + width > s->screen_width || - top + height > s->screen_height) - return -EINVAL; - } - s->image_count++; + /* verify that all the image is inside the screen dimensions */ + if (left + width > s->screen_width || + top + height > s->screen_height) + return -EINVAL; line = av_malloc(width); if (!line) @@ -279,8 +311,11 @@ static int gif_read_image(AVFormatContext * s1, AVPacket * pkt) GLZWDecodeInit(s, code_size); /* read all the image and transcode it to RGB24 (horrible) */ - linesize = s->screen_width * 3; - ptr = s->image_buf + top * linesize + (left * 3); + linesize = s->image_linesize; + ptr1 = s->image_buf + top * linesize + (left * 3); + ptr = ptr1; + pass = 0; + y1 = 0; for (y = 0; y < height; y++) { GLZWDecode(s, line, width); d = ptr; @@ -293,29 +328,51 @@ static int gif_read_image(AVFormatContext * s1, AVPacket * pkt) d += 3; sptr++; } - ptr += linesize; + if (is_interleaved) { + switch(pass) { + default: + case 0: + case 1: + y1 += 8; + ptr += linesize * 8; + if (y1 >= height) { + y1 = 4; + if (pass == 0) + ptr = ptr1 + linesize * 4; + else + ptr = ptr1 + linesize * 2; + pass++; + } + break; + case 2: + y1 += 4; + ptr += linesize * 4; + if (y1 >= height) { + y1 = 1; + ptr = ptr1 + linesize; + pass++; + } + break; + case 3: + y1 += 2; + ptr += linesize * 2; + break; + } + } else { + ptr += linesize; + } } av_free(line); /* read the garbage data until end marker is found */ while (!s->eob_reached) GetCode(s); - - /* output image */ - /* XXX: avoid copying */ - if (av_new_packet(pkt, s->screen_width * s->screen_height * 3)) { - av_free(line); - return -EIO; - } - pkt->stream_index = 0; - memcpy(pkt->data, s->image_buf, s->screen_width * s->screen_height * 3); return 0; } -static int gif_read_extension(AVFormatContext * s1) +static int gif_read_extension(GifState *s) { - GifState *s = s1->priv_data; - ByteIOContext *f = &s1->pb; + ByteIOContext *f = s->f; int ext_code, ext_len, i, gce_flags, gce_transparent_index; /* extension */ @@ -359,12 +416,9 @@ static int gif_read_extension(AVFormatContext * s1) return 0; } -static int gif_read_header(AVFormatContext * s1, - AVFormatParameters * ap) +static int gif_read_header1(GifState *s) { - GifState *s = s1->priv_data; - ByteIOContext *f = &s1->pb; - AVStream *st; + ByteIOContext *f = s->f; uint8_t sig[6]; int ret, v, n; int has_global_palette; @@ -396,25 +450,12 @@ static int gif_read_header(AVFormatContext * s1, n = 1 << s->bits_per_pixel; get_buffer(f, s->global_palette, n * 3); } - /* now we are ready: build format streams */ - st = av_new_stream(s1, 0); - if (!st) - return -1; - - st->codec.codec_type = CODEC_TYPE_VIDEO; - st->codec.codec_id = CODEC_ID_RAWVIDEO; - st->codec.frame_rate = 5 * FRAME_RATE_BASE; - /* XXX: check if screen size is always valid */ - st->codec.width = s->screen_width; - st->codec.height = s->screen_height; - st->codec.pix_fmt = PIX_FMT_RGB24; return 0; } -static int gif_read_packet(AVFormatContext * s1, - AVPacket * pkt) +static int gif_parse_next_image(GifState *s) { - ByteIOContext *f = &s1->pb; + ByteIOContext *f = s->f; int ret, code; for (;;) { @@ -424,7 +465,7 @@ static int gif_read_packet(AVFormatContext * s1, #endif switch (code) { case ',': - if (gif_read_image(s1, pkt) < 0) + if (gif_read_image(s) < 0) return -EIO; ret = 0; goto the_end; @@ -433,7 +474,7 @@ static int gif_read_packet(AVFormatContext * s1, ret = -EIO; goto the_end; case '!': - if (gif_read_extension(s1) < 0) + if (gif_read_extension(s) < 0) return -EIO; break; case EOF: @@ -447,6 +488,56 @@ static int gif_read_packet(AVFormatContext * s1, return ret; } +static int gif_read_header(AVFormatContext * s1, + AVFormatParameters * ap) +{ + GifState *s = s1->priv_data; + ByteIOContext *f = &s1->pb; + AVStream *st; + + s->f = f; + if (gif_read_header1(s) < 0) + return -1; + + /* allocate image buffer */ + s->image_linesize = s->screen_width * 3; + s->image_buf = av_malloc(s->screen_height * s->image_linesize); + if (!s->image_buf) + return -ENOMEM; + /* now we are ready: build format streams */ + st = av_new_stream(s1, 0); + if (!st) + return -1; + + st->codec.codec_type = CODEC_TYPE_VIDEO; + st->codec.codec_id = CODEC_ID_RAWVIDEO; + st->codec.frame_rate = 5 * FRAME_RATE_BASE; + /* XXX: check if screen size is always valid */ + st->codec.width = s->screen_width; + st->codec.height = s->screen_height; + st->codec.pix_fmt = PIX_FMT_RGB24; + return 0; +} + +static int gif_read_packet(AVFormatContext * s1, + AVPacket * pkt) +{ + GifState *s = s1->priv_data; + int ret; + + ret = gif_parse_next_image(s); + if (ret < 0) + return ret; + + /* XXX: avoid copying */ + if (av_new_packet(pkt, s->screen_width * s->screen_height * 3)) { + return -EIO; + } + pkt->stream_index = 0; + memcpy(pkt->data, s->image_buf, s->screen_width * s->screen_height * 3); + return 0; +} + static int gif_read_close(AVFormatContext *s1) { GifState *s = s1->priv_data; @@ -454,13 +545,48 @@ static int gif_read_close(AVFormatContext *s1) return 0; } +/* read gif as image */ +static int gif_read(ByteIOContext *f, + int (*alloc_cb)(void *opaque, AVImageInfo *info), void *opaque) +{ + GifState s1, *s = &s1; + AVImageInfo info1, *info = &info1; + int ret; + + memset(s, 0, sizeof(GifState)); + s->f = f; + if (gif_read_header1(s) < 0) + return -1; + info->width = s->screen_width; + info->height = s->screen_height; + info->pix_fmt = PIX_FMT_RGB24; + ret = alloc_cb(opaque, info); + if (ret) + return ret; + s->image_buf = info->pict.data[0]; + s->image_linesize = info->pict.linesize[0]; + + if (gif_parse_next_image(s) < 0) + return -1; + return 0; +} + AVInputFormat gif_iformat = { "gif", "gif format", sizeof(GifState), - gif_probe, + gif_video_probe, gif_read_header, gif_read_packet, gif_read_close, }; + +AVImageFormat gif_image_format = { + "gif", + "gif", + gif_image_probe, + gif_read, + (1 << PIX_FMT_RGB24), + gif_write, +}; |