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parse mpeg2 gop header time code and use it

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Originally committed as revision 17149 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Baptiste Coudurier 2009-02-11 08:02:23 +00:00
parent 7c9668cf8a
commit 7a10119057
1 changed files with 22 additions and 4 deletions
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26
libavformat/mxfenc.c
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@ -126,7 +126,7 @@ typedef struct MXFContext {
uint64_t duration;
AVStream *timecode_track;
int timecode_base; ///< rounded time code base (25 or 30)
int timecode_start; ///< value from mpeg-2 essence gop header
int timecode_start; ///< frame number computed from mpeg-2 gop header timecode
int timecode_drop_frame; ///< time code use drop frame method frop mpeg-2 essence gop header
} MXFContext;
@ -1208,6 +1208,7 @@ static const UID *mxf_get_mpeg2_codec_ul(AVCodecContext *avctx)
static int mxf_parse_mpeg2_frame(AVFormatContext *s, AVStream *st, AVPacket *pkt, int *flags)
{
MXFStreamContext *sc = st->priv_data;
MXFContext *mxf = s->priv_data;
uint32_t c = -1;
int i;
@ -1224,8 +1225,25 @@ static int mxf_parse_mpeg2_frame(AVFormatContext *s, AVStream *st, AVPacket *pkt
break;
}
} else if (c == 0x1b8) { // gop
if (i + 4 < pkt->size && pkt->data[i+4]>>6 & 0x01) // closed
*flags |= 0x80; // random access
if (i + 4 < pkt->size) {
if (pkt->data[i+4]>>6 & 0x01) // closed
*flags |= 0x80; // random access
if (!mxf->header_written) {
unsigned hours = (pkt->data[i+1]>>2) & 0x1f;
unsigned minutes = ((pkt->data[i+1] & 0x03) << 4) | (pkt->data[i+2]>>4);
unsigned seconds = ((pkt->data[i+2] & 0x07) << 3) | (pkt->data[i+3]>>5);
unsigned frames = ((pkt->data[i+3] & 0x1f) << 1) | (pkt->data[i+4]>>7);
mxf->timecode_drop_frame = !!(pkt->data[i+1] & 0x80);
mxf->timecode_start = (hours*3600 + minutes*60 + seconds) *
mxf->timecode_base + frames;
if (mxf->timecode_drop_frame) {
unsigned tminutes = 60 * hours + minutes;
mxf->timecode_start -= 2 * (tminutes - tminutes / 10);
}
av_log(s, AV_LOG_DEBUG, "frame %d %d:%d:%d%c%d\n", mxf->timecode_start,
hours, minutes, seconds, mxf->timecode_drop_frame ? ';':':', frames);
}
}
} else if (c == 0x1b3) { // seq
*flags |= 0x40;
} else if (c == 0x100) { // pic
@ -1372,7 +1390,7 @@ static void mxf_write_system_item(AVFormatContext *s)
unsigned frame;
uint32_t time_code;
frame = mxf->last_indexed_edit_unit + mxf->edit_units_count;
frame = mxf->timecode_start + mxf->last_indexed_edit_unit + mxf->edit_units_count;
// write system metadata pack
put_buffer(pb, system_metadata_pack_key, 16);