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Lift restrictions on channel mask 

See also https://github.com/ietf-wg-cellar/flac-specification/pull/182
This commit is contained in:
Martijn van Beurden 2023-01-09 11:00:51 +01:00 committed by GitHub
parent 6ea23b0fd3
commit fe0bf2309a
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 4 additions and 105 deletions
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109
src/flac/encode.c
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@ -170,9 +170,6 @@ static FLAC__bool read_uint64(FILE *f, FLAC__bool big_endian, FLAC__uint64 *val,
static FLAC__bool read_sane_extended(FILE *f, FLAC__uint32 *val, const char *fn);
static FLAC__bool fskip_ahead(FILE *f, FLAC__uint64 offset);
static uint32_t count_channel_mask_bits(FLAC__uint32 mask);
#if 0
static FLAC__uint32 limit_channel_mask(FLAC__uint32 mask, uint32_t channels);
#endif
static FLAC__bool get_sample_info_raw(EncoderSession *e, encode_options_t options)
{
@ -419,92 +416,11 @@ static FLAC__bool get_sample_info_wave(EncoderSession *e, encode_options_t optio
/* channel mask */
if(!read_uint32(e->fin, /*big_endian=*/false, &channel_mask, e->inbasefilename))
return false;
/* for mono/stereo and unassigned channels, we fake the mask */
if(channel_mask == 0) {
if(channels == 1)
channel_mask = 0x0004;
else if(channels == 2)
channel_mask = 0x0003;
}
/* set channel mapping */
/* FLAC order follows SMPTE and WAVEFORMATEXTENSIBLE but with fewer channels, which are: */
/* front left, front right, front center, LFE, back left, back right, back center, side left, side right */
/* the default mapping is sufficient for 1-8 channels */
#if 0
/* @@@ example for dolby/vorbis order, for reference later in case it becomes important */
if(
options.channel_map_none ||
channel_mask == 0x0001 || /* 1 channel: (mono) */
channel_mask == 0x0003 || /* 2 channels: front left, front right */
channel_mask == 0x0033 || /* 4 channels: front left, front right, back left, back right */
channel_mask == 0x0603 /* 4 channels: front left, front right, side left, side right */
) {
/* keep default channel order */
}
else if(
channel_mask == 0x0007 || /* 3 channels: front left, front right, front center */
channel_mask == 0x0037 || /* 5 channels: front left, front right, front center, back left, back right */
channel_mask == 0x0607 /* 5 channels: front left, front right, front center, side left, side right */
) {
/* to dolby order: front left, center, front right [, surround left, surround right ] */
channel_map[1] = 2;
channel_map[2] = 1;
}
else if(
channel_mask == 0x003f || /* 6 channels: front left, front right, front center, LFE, back left, back right */
channel_mask == 0x060f || /* 6 channels: front left, front right, front center, LFE, side left, side right */
channel_mask == 0x070f || /* 7 channels: front left, front right, front center, LFE, back center, side left, side right */
channel_mask == 0x063f /* 8 channels: front left, front right, front center, LFE, back left, back right, side left, side right */
) {
/* to dolby order: front left, center, front right, surround left, surround right, LFE */
channel_map[1] = 2;
channel_map[2] = 1;
channel_map[3] = 5;
channel_map[4] = 3;
channel_map[5] = 4;
}
#else
if(
options.channel_map_none ||
channel_mask == 0x0001 || /* 1 channel: front left */
channel_mask == 0x0002 || /* 1 channel: front right */
channel_mask == 0x0004 || /* 1 channel: mono or front center */
channel_mask == 0x0003 || /* 2 channels: front left, front right */
channel_mask == 0x0007 || /* 3 channels: front left, front right, front center */
channel_mask == 0x0033 || /* 4 channels: front left, front right, back left, back right */
channel_mask == 0x0603 || /* 4 channels: front left, front right, side left, side right */
channel_mask == 0x0037 || /* 5 channels: front left, front right, front center, back left, back right */
channel_mask == 0x0607 || /* 5 channels: front left, front right, front center, side left, side right */
channel_mask == 0x003f || /* 6 channels: front left, front right, front center, LFE, back left, back right */
channel_mask == 0x060f || /* 6 channels: front left, front right, front center, LFE, side left, side right */
channel_mask == 0x070f || /* 7 channels: front left, front right, front center, LFE, back center, side left, side right */
channel_mask == 0x063f /* 8 channels: front left, front right, front center, LFE, back left, back right, side left, side right */
) {
/* keep default channel order */
}
#endif
else {
flac__utils_printf(stderr, 1, "%s: ERROR: WAVEFORMATEXTENSIBLE chunk with unsupported channel mask=0x%04X\n\nUse --channel-map=none option to encode the input\n", e->inbasefilename, (uint32_t)channel_mask);
return false;
}
if(!options.channel_map_none) {
if(count_channel_mask_bits(channel_mask) < channels) {
flac__utils_printf(stderr, 1, "%s: ERROR: WAVEFORMATEXTENSIBLE chunk: channel mask 0x%04X has unassigned channels (#channels=%u)\n", e->inbasefilename, (uint32_t)channel_mask, channels);
if(count_channel_mask_bits(channel_mask) > channels) {
flac__utils_printf(stderr, 1, "%s: WARNING: WAVEFORMATEXTENSIBLE chunk: channel mask 0x%04X has extra bits for non-existant channels (#channels=%u)\n", e->inbasefilename, (uint32_t)channel_mask, channels);
if(e->treat_warnings_as_errors)
return false;
}
#if 0
/* supporting this is too difficult with channel mapping; e.g. what if mask is 0x003f but #channels=4?
* there would be holes in the order that would have to be filled in, or the mask would have to be
* limited and the logic above rerun to see if it still fits into the FLAC mapping.
*/
else if(count_channel_mask_bits(channel_mask) > channels)
channel_mask = limit_channel_mask(channel_mask, channels);
#else
else if(count_channel_mask_bits(channel_mask) > channels) {
flac__utils_printf(stderr, 1, "%s: ERROR: WAVEFORMATEXTENSIBLE chunk: channel mask 0x%04X has extra bits for non-existant channels (#channels=%u)\n", e->inbasefilename, (uint32_t)channel_mask, channels);
return false;
}
#endif
}
/* first part of GUID */
if(!read_uint16(e->fin, /*big_endian=*/false, &x, e->inbasefilename))
@ -2965,20 +2881,3 @@ uint32_t count_channel_mask_bits(FLAC__uint32 mask)
}
return count;
}
#if 0
FLAC__uint32 limit_channel_mask(FLAC__uint32 mask, uint32_t channels)
{
FLAC__uint32 x = 0x80000000;
uint32_t count = count_channel_mask_bits(mask);
while(x && count > channels) {
if(mask & x) {
mask &= ~x;
count--;
}
x >>= 1;
}
FLAC__ASSERT(count_channel_mask_bits(mask) == channels);
return mask;
}
#endif