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author | Mike Melanson <mike@multimedia.cx> | 2003-05-10 04:30:29 +0000 |
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committer | Mike Melanson <mike@multimedia.cx> | 2003-05-10 04:30:29 +0000 |
commit | 89a79364ed80746094cfb6b585bb4d2a1c5ac03d (patch) | |
tree | 7fff2913ed6ce5f22f4bb413ec6c8012e37036b9 /libavcodec/svq3.c | |
parent | 8b82a9567547f1ca7ab54f97982e180f42795664 (diff) | |
download | ffmpeg-streaming-89a79364ed80746094cfb6b585bb4d2a1c5ac03d.zip ffmpeg-streaming-89a79364ed80746094cfb6b585bb4d2a1c5ac03d.tar.gz |
change the way the ImageDescription is passed to the decoder
Originally committed as revision 1846 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/svq3.c')
-rw-r--r-- | libavcodec/svq3.c | 32 |
1 files changed, 19 insertions, 13 deletions
diff --git a/libavcodec/svq3.c b/libavcodec/svq3.c index 6d24a5c..0cd9279 100644 --- a/libavcodec/svq3.c +++ b/libavcodec/svq3.c @@ -18,17 +18,23 @@ * * How to use this decoder: * SVQ3 data is transported within Apple Quicktime files. Quicktime files - * have stsd atoms to describe media trak properties. Sometimes the stsd - * atom contains information that the decoder must know in order to function - * properly. Such is the case with SVQ3. In order to get the best use out - * of this decoder, the calling app must make the video stsd atom available + * have stsd atoms to describe media trak properties. A stsd atom for a + * video trak contains 1 or more ImageDescription atoms. These atoms begin + * with the 4-byte length of the atom followed by the codec fourcc. Some + * decoders need information in this atom to operate correctly. Such + * is the case with SVQ3. In order to get the best use out of this decoder, + * the calling app must make the SVQ3 ImageDescription atom available * via the AVCodecContext's extradata[_size] field: * - * AVCodecContext.extradata = pointer to stsd, first characters are expected - * to be 's', 't', 's', and 'd', NOT the atom length - * AVCodecContext.extradata_size = size of stsd atom memory buffer (which - * will be the same as the stsd atom size field from the QT file, minus 4 - * bytes since the length is missing. + * AVCodecContext.extradata = pointer to ImageDescription, first characters + * are expected to be 'S', 'V', 'Q', and '3', NOT the 4-byte atom length + * AVCodecContext.extradata_size = size of ImageDescription atom memory + * buffer (which will be the same as the ImageDescription atom size field + * from the QT file, minus 4 bytes since the length is missing) + * + * You will know you have these parameters passed correctly when the decoder + * correctly decodes this file: + * ftp://ftp.mplayerhq.hu/MPlayer/samples/V-codecs/SVQ3/Vertical400kbit.sorenson3.mov * */ @@ -667,12 +673,12 @@ static int svq3_decode_frame (AVCodecContext *avctx, alloc_tables (h); } - if (avctx->extradata && avctx->extradata_size >= 115 - && !memcmp (avctx->extradata, "stsd", 4)) { + if (avctx->extradata && avctx->extradata_size >= 0x63 + && !memcmp (avctx->extradata, "SVQ3", 4)) { - uint8_t *stsd = (uint8_t *) avctx->extradata + 114; + uint8_t *stsd = (uint8_t *) avctx->extradata + 0x62; - if ((*stsd >> 5) != 7 || avctx->extradata_size >= 118) { + if ((*stsd >> 5) != 7 || avctx->extradata_size >= 0x66) { if ((*stsd >> 5) == 7) { stsd += 3; /* skip width, height (12 bits each) */ |