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avformat/mxfdec: Detect field_order based on video_line_map

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Read video_line_map from MXF generic picture essence descriptor and use
it to derive the coded field order. Use field_dominance to derive the
display field order from coded field order. If field_dominance is not
available the default value "1" is used as defined in SMPTE S377-1.

Fixes field_order detection for a bunch of DV/DVCPRO files. The heuristic
for deriving coded field order from video_line_map is inspired by
MediaInfo.

Signed-off-by: Tobias Rapp <t.rapp@noa-archive.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
pull/238/merge
Tobias Rapp 9 years ago committed by Michael Niedermayer
parent ee5f0f1d35
commit e3196b6862
1 changed files with 60 additions and 15 deletions
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  1. 75
      libavformat/mxfdec.c

75
libavformat/mxfdec.c
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@ -173,8 +173,10 @@ typedef struct MXFDescriptor {
int width;
int height; /* Field height, not frame height */
int frame_layout; /* See MXFFrameLayout enum */
#define MXF_TFF 1
#define MXF_BFF 2
int video_line_map[2];
#define MXF_FIELD_DOMINANCE_DEFAULT 0
#define MXF_FIELD_DOMINANCE_FF 1 /* coded first, displayed first */
#define MXF_FIELD_DOMINANCE_FL 2 /* coded first, displayed last */
int field_dominance;
int channels;
int bits_per_sample;
@ -968,6 +970,8 @@ static void mxf_read_pixel_layout(AVIOContext *pb, MXFDescriptor *descriptor)
static int mxf_read_generic_descriptor(void *arg, AVIOContext *pb, int tag, int size, UID uid, int64_t klv_offset)
{
MXFDescriptor *descriptor = arg;
int entry_count, entry_size;
switch(tag) {
case 0x3F01:
return mxf_read_strong_ref_array(pb, &descriptor->sub_descriptors_refs,
@ -996,6 +1000,21 @@ static int mxf_read_generic_descriptor(void *arg, AVIOContext *pb, int tag, int
case 0x320C:
descriptor->frame_layout = avio_r8(pb);
break;
case 0x320D:
entry_count = avio_rb32(pb);
entry_size = avio_rb32(pb);
if (entry_size == 4) {
if (entry_count > 0)
descriptor->video_line_map[0] = avio_rb32(pb);
else
descriptor->video_line_map[0] = 0;
if (entry_count > 1)
descriptor->video_line_map[1] = avio_rb32(pb);
else
descriptor->video_line_map[1] = 0;
} else
av_log(NULL, AV_LOG_WARNING, "VideoLineMap element size %d currently not supported\n", entry_size);
break;
case 0x320E:
descriptor->aspect_ratio.num = avio_rb32(pb);
descriptor->aspect_ratio.den = avio_rb32(pb);
@ -2044,19 +2063,45 @@ static int mxf_parse_structural_metadata(MXFContext *mxf)
case SegmentedFrame:
st->codecpar->field_order = AV_FIELD_PROGRESSIVE;
case SeparateFields:
switch (descriptor->field_dominance) {
case MXF_TFF:
st->codecpar->field_order = AV_FIELD_TT;
break;
case MXF_BFF:
st->codecpar->field_order = AV_FIELD_BB;
break;
default:
avpriv_request_sample(mxf->fc,
"Field dominance %d support",
descriptor->field_dominance);
case 0: // we already have many samples with field_dominance == unknown
break;
av_log(mxf->fc, AV_LOG_DEBUG, "video_line_map: (%d, %d), field_dominance: %d\n",
descriptor->video_line_map[0], descriptor->video_line_map[1],
descriptor->field_dominance);
if ((descriptor->video_line_map[0] > 0) && (descriptor->video_line_map[1] > 0)) {
/* Detect coded field order from VideoLineMap:
* (even, even) => bottom field coded first
* (even, odd) => top field coded first
* (odd, even) => top field coded first
* (odd, odd) => bottom field coded first
*/
if ((descriptor->video_line_map[0] + descriptor->video_line_map[1]) % 2) {
switch (descriptor->field_dominance) {
case MXF_FIELD_DOMINANCE_DEFAULT:
case MXF_FIELD_DOMINANCE_FF:
st->codecpar->field_order = AV_FIELD_TT;
break;
case MXF_FIELD_DOMINANCE_FL:
st->codecpar->field_order = AV_FIELD_TB;
break;
default:
avpriv_request_sample(mxf->fc,
"Field dominance %d support",
descriptor->field_dominance);
}
} else {
switch (descriptor->field_dominance) {
case MXF_FIELD_DOMINANCE_DEFAULT:
case MXF_FIELD_DOMINANCE_FF:
st->codecpar->field_order = AV_FIELD_BB;
break;
case MXF_FIELD_DOMINANCE_FL:
st->codecpar->field_order = AV_FIELD_BT;
break;
default:
avpriv_request_sample(mxf->fc,
"Field dominance %d support",
descriptor->field_dominance);
}
}
}
/* Turn field height into frame height. */
st->codecpar->height *= 2;

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