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avformat/mov_chan: rework ff_mov_read_chnl 

A lot of changes and fixes to channel layout parsing, notably
- get rid of dynamic allocation of channel positions
- signal unimplemented speaker positions as unknown instead of failure, but
  warn the user about it
- native order, and that a single channel only appears once was always assumed
  for less than 64 channels, obviously this was incorrect

Signed-off-by: Marton Balint <cus@passwd.hu>
This commit is contained in:
Marton Balint 2024-02-10 01:44:01 +01:00
parent f8f2142d61
commit b81ed729ec
2 changed files with 30 additions and 90 deletions
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114
libavformat/mov_chan.c
View File

@ -804,66 +804,6 @@ int ff_mov_get_channel_positions_from_layout(const AVChannelLayout *layout,
return 0;
}
int ff_mov_get_layout_from_channel_positions(const uint8_t *position, int position_num,
AVChannelLayout *layout)
{
int ret;
enum AVChannel channel;
av_channel_layout_uninit(layout);
if (position_num <= 63) {
layout->order = AV_CHANNEL_ORDER_NATIVE;
layout->nb_channels = position_num;
for (int i = 0; i < position_num; i++) {
if (position[i] >= FF_ARRAY_ELEMS(iso_channel_position)) {
ret = AVERROR_PATCHWELCOME;
goto error;
}
channel = iso_channel_position[position[i]];
// unsupported layout
if (channel == AV_CHAN_NONE) {
ret = AVERROR_PATCHWELCOME;
goto error;
}
layout->u.mask |= 1ULL << channel;
}
} else {
layout->order = AV_CHANNEL_ORDER_CUSTOM;
layout->nb_channels = position_num;
layout->u.map = av_calloc(position_num, sizeof(*layout->u.map));
if (!layout->u.map) {
ret = AVERROR(ENOMEM);
goto error;
}
for (int i = 0; i < position_num; i++) {
if (position[i] >= FF_ARRAY_ELEMS(iso_channel_position)) {
ret = AVERROR_PATCHWELCOME;
goto error;
}
channel = iso_channel_position[position[i]];
// unsupported layout
if (channel == AV_CHAN_NONE) {
ret = AVERROR_PATCHWELCOME;
goto error;
}
layout->u.map[i].id = channel;
}
}
return 0;
error:
av_channel_layout_uninit(layout);
return ret;
}
int ff_mov_read_chnl(AVFormatContext *s, AVIOContext *pb, AVStream *st)
{
int stream_structure = avio_r8(pb);
@ -875,33 +815,39 @@ int ff_mov_read_chnl(AVFormatContext *s, AVIOContext *pb, AVStream *st)
av_log(s, AV_LOG_TRACE, "'chnl' layout %d\n", layout);
if (!layout) {
uint8_t *positions = av_malloc(st->codecpar->ch_layout.nb_channels);
AVChannelLayout *ch_layout = &st->codecpar->ch_layout;
int nb_channels = ch_layout->nb_channels;
if (!positions)
return AVERROR(ENOMEM);
for (int i = 0; i < st->codecpar->ch_layout.nb_channels; i++) {
int speaker_pos = avio_r8(pb);
av_log(s, AV_LOG_TRACE, "speaker_position %d\n", speaker_pos);
if (speaker_pos == 126) { // explicit position
avpriv_request_sample(s, "explicit position");
av_freep(&positions);
return AVERROR_PATCHWELCOME;
} else {
positions[i] = speaker_pos;
}
}
ret = ff_mov_get_layout_from_channel_positions(positions,
st->codecpar->ch_layout.nb_channels,
&st->codecpar->ch_layout);
av_freep(&positions);
if (ret) {
av_log(s, AV_LOG_ERROR,
"get channel layout from speaker positions failed, %s\n",
av_err2str(ret));
av_channel_layout_uninit(ch_layout);
ret = av_channel_layout_custom_init(ch_layout, nb_channels);
if (ret < 0)
return ret;
for (int i = 0; i < nb_channels; i++) {
int speaker_pos = avio_r8(pb);
enum AVChannel channel;
if (speaker_pos == 126) // explicit position
avio_skip(pb, 3); // azimuth, elevation
if (speaker_pos >= FF_ARRAY_ELEMS(iso_channel_position))
channel = AV_CHAN_NONE;
else
channel = iso_channel_position[speaker_pos];
if (channel == AV_CHAN_NONE) {
av_log(s, AV_LOG_WARNING, "speaker position %d is not implemented\n", speaker_pos);
channel = AV_CHAN_UNKNOWN;
}
ch_layout->u.map[i].id = channel;
}
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))
return ret;
} else {
uint64_t omitted_channel_map = avio_rb64(pb);

6
libavformat/mov_chan.h
View File

@ -183,12 +183,6 @@ int ff_mov_get_channel_layout_from_config(int config, AVChannelLayout *layout);
int ff_mov_get_channel_positions_from_layout(const AVChannelLayout *layout,
uint8_t *position, int position_num);
/**
* Get AVChannelLayout from ISO/IEC 23001-8 OutputChannelPosition.
*/
int ff_mov_get_layout_from_channel_positions(const uint8_t *position, int position_num,
AVChannelLayout *layout);
/**
* Read 'chnl' tag from the input stream.
*