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avformat/mov_chan: add support for reading custom channel layouts when layout_tag == 0 

Signed-off-by: Marton Balint <cus@passwd.hu>
This commit is contained in:
Marton Balint 2024-01-30 00:21:14 +01:00
parent 66386bf2a2
commit 106527d2e5
1 changed files with 57 additions and 46 deletions
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103
libavformat/mov_chan.c
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@ -377,23 +377,23 @@ static uint64_t mov_get_channel_layout(uint32_t tag, uint32_t bitmap)
return layout_map[i].layout;
}
static uint64_t mov_get_channel_mask(uint32_t label)
static enum AVChannel mov_get_channel_id(uint32_t label)
{
if (label == 0)
return 0;
return AV_CHAN_UNUSED;
if (label <= 18)
return 1U << (label - 1);
return (label - 1);
if (label == 35)
return AV_CH_WIDE_LEFT;
return AV_CHAN_WIDE_LEFT;
if (label == 36)
return AV_CH_WIDE_RIGHT;
return AV_CHAN_WIDE_RIGHT;
if (label == 37)
return AV_CH_LOW_FREQUENCY_2;
return AV_CHAN_LOW_FREQUENCY_2;
if (label == 38)
return AV_CH_STEREO_LEFT;
return AV_CHAN_STEREO_LEFT;
if (label == 39)
return AV_CH_STEREO_RIGHT;
return 0;
return AV_CHAN_STEREO_RIGHT;
return AV_CHAN_UNKNOWN;
}
static uint32_t mov_get_channel_label(enum AVChannel channel)
@ -497,8 +497,8 @@ int ff_mov_read_chan(AVFormatContext *s, AVIOContext *pb, AVStream *st,
int64_t size)
{
uint32_t layout_tag, bitmap, num_descr;
uint64_t label_mask, mask = 0;
int i;
int ret;
AVChannelLayout *ch_layout = &st->codecpar->ch_layout;
if (size < 12)
return AVERROR_INVALIDDATA;
@ -514,47 +514,58 @@ int ff_mov_read_chan(AVFormatContext *s, AVIOContext *pb, AVStream *st,
if (size < 12ULL + num_descr * 20ULL)
return 0;
label_mask = 0;
for (i = 0; i < num_descr; i++) {
uint32_t label;
if (pb->eof_reached) {
av_log(s, AV_LOG_ERROR,
"reached EOF while reading channel layout\n");
return AVERROR_INVALIDDATA;
}
label = avio_rb32(pb); // mChannelLabel
avio_rb32(pb); // mChannelFlags
avio_rl32(pb); // mCoordinates[0]
avio_rl32(pb); // mCoordinates[1]
avio_rl32(pb); // mCoordinates[2]
size -= 20;
if (layout_tag == 0) {
uint64_t mask_incr = mov_get_channel_mask(label);
if (mask_incr == 0 || mask_incr <= label_mask) {
label_mask = 0;
break;
}
label_mask |= mask_incr;
}
}
if (layout_tag == 0) {
if (label_mask)
mask = label_mask;
} else
mask = mov_get_channel_layout(layout_tag, bitmap);
int nb_channels = ch_layout->nb_channels ? ch_layout->nb_channels : num_descr;
if (num_descr > nb_channels) {
av_log(s, AV_LOG_WARNING, "got %d channel descriptions, capping to the number of channels %d\n",
num_descr, nb_channels);
num_descr = nb_channels;
}
if (mask) {
if (!st->codecpar->ch_layout.nb_channels || av_popcount64(mask) == st->codecpar->ch_layout.nb_channels) {
av_channel_layout_uninit(&st->codecpar->ch_layout);
av_channel_layout_from_mask(&st->codecpar->ch_layout, mask);
} else {
av_log(s, AV_LOG_WARNING, "ignoring channel layout with %d channels because the real number of channels is %d\n",
av_popcount64(mask), st->codecpar->ch_layout.nb_channels);
av_channel_layout_uninit(ch_layout);
ret = av_channel_layout_custom_init(ch_layout, nb_channels);
if (ret < 0)
goto out;
for (int i = 0; i < num_descr; i++) {
uint32_t label;
if (pb->eof_reached) {
av_log(s, AV_LOG_ERROR,
"reached EOF while reading channel layout\n");
return AVERROR_INVALIDDATA;
}
label = avio_rb32(pb); // mChannelLabel
avio_rb32(pb); // mChannelFlags
avio_rl32(pb); // mCoordinates[0]
avio_rl32(pb); // mCoordinates[1]
avio_rl32(pb); // mCoordinates[2]
size -= 20;
ch_layout->u.map[i].id = mov_get_channel_id(label);
}
ret = av_channel_layout_retype(ch_layout, AV_CHANNEL_ORDER_NATIVE, AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS);
if (ret == AVERROR(ENOSYS))
ret = av_channel_layout_retype(ch_layout, AV_CHANNEL_ORDER_UNSPEC, AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS);
if (ret < 0 && ret != AVERROR(ENOSYS))
goto out;
} else {
uint64_t mask = mov_get_channel_layout(layout_tag, bitmap);
if (mask) {
if (!ch_layout->nb_channels || av_popcount64(mask) == ch_layout->nb_channels) {
av_channel_layout_uninit(ch_layout);
av_channel_layout_from_mask(ch_layout, mask);
} else {
av_log(s, AV_LOG_WARNING, "ignoring channel layout with %d channels because number of channels is %d\n",
av_popcount64(mask), ch_layout->nb_channels);
}
}
}
ret = 0;
out:
avio_skip(pb, size - 12);
return 0;
return ret;
}
/* ISO/IEC 23001-8, 8.2 */