- Only parse the defined masks in dwChannelMask, unless strict_std_compliance is less than normal. This matches with the behaviour of the wav muxer. - Ignore additional bits in dwChannelMasks as the MS documentation suggests [1] - Assume UNKNOWN channels for missing bits as the MS documentation suggests [1]
[1] https://learn.microsoft.com/en-us/previous-versions/windows/hardware/design/dn653308(v=vs.85)#details-about-dwchannelmask Signed-off-by: Marton Balint <c...@passwd.hu> --- libavformat/riffdec.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/libavformat/riffdec.c b/libavformat/riffdec.c index 6cc912133c..0c7b2c6bdb 100644 --- a/libavformat/riffdec.c +++ b/libavformat/riffdec.c @@ -58,7 +58,7 @@ enum AVCodecID ff_codec_guid_get_id(const AVCodecGuid *guids, ff_asf_guid guid) * an openended structure. */ -static void parse_waveformatex(AVFormatContext *ctx, AVIOContext *pb, AVCodecParameters *par) +static int parse_waveformatex(AVFormatContext *ctx, AVIOContext *pb, AVCodecParameters *par, int channels) { ff_asf_guid subformat; int bps; @@ -69,7 +69,26 @@ static void parse_waveformatex(AVFormatContext *ctx, AVIOContext *pb, AVCodecPar par->bits_per_coded_sample = bps; mask = avio_rl32(pb); /* dwChannelMask */ - av_channel_layout_from_mask(&par->ch_layout, mask); + if (ctx->strict_std_compliance >= FF_COMPLIANCE_NORMAL) + mask &= 0x3ffff; + + /* According to MS docs, most significant bits should be ignored if mask + * has more bits than the number of channels */ + while (av_popcount64(mask) > channels) + mask &= ~(1LL << av_log2(mask)); + + /* If the mask has less bits than channels, then we assign the remaining + * channels as UNKNOWN. */ + if (mask && av_popcount64(mask) < channels) { + int ret = av_channel_layout_custom_init(&par->ch_layout, channels); + if (ret < 0) + return ret; + for (int i = 0, idx = 0; mask; i++, mask >>= 1) + if (mask & 1) + par->ch_layout.u.map[idx++].id = i; + } else { + av_channel_layout_from_mask(&par->ch_layout, mask); + } ff_get_guid(pb, &subformat); if (!memcmp(subformat + 4, @@ -88,6 +107,7 @@ static void parse_waveformatex(AVFormatContext *ctx, AVIOContext *pb, AVCodecPar "unknown subformat:"FF_PRI_GUID"\n", FF_ARG_GUID(subformat)); } + return 0; } /* "big_endian" values are needed for RIFX file format */ @@ -145,7 +165,9 @@ int ff_get_wav_header(AVFormatContext *ctx, AVIOContext *pb, size -= 18; cbSize = FFMIN(size, cbSize); if (cbSize >= 22 && id == 0xfffe) { /* WAVEFORMATEXTENSIBLE */ - parse_waveformatex(ctx, pb, par); + ret = parse_waveformatex(ctx, pb, par, channels); + if (ret < 0) + return ret; cbSize -= 22; size -= 22; } -- 2.35.3 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
