[FFmpeg-devel] [PATCH v2] avformat/westwood_aud: Adds PCM format demux.

[Aidan R]

tis 2019-03-19 klockan 22:53 +0000 skrev Aidan R:
> @@ -69,13 +75,25 @@ static int wsaud_probe(AVProbeData *p)
>>      if (p->buf[10] & 0xFC)
>>          return 0;
>>  
>> -    if (p->buf[11] != 99 && p->buf[11] != 1)
>> +    /* valid format values are 99 == adpcm, 1 == snd1 and 0 == pcm */
>> +    if (p->buf[11] != 99 && p->buf[11] != 1 && p->buf[11] != 0)
>>          return 0;
>>  
>> -    /* read ahead to the first audio chunk and validate the first header signature */
>> -    if (AV_RL32(&p->buf[16]) != AUD_CHUNK_SIGNATURE)
>> +    /* read ahead to the first audio chunk and validate the first header
>> +     * signature pcm format does not use a chunk format, so don't check
>
> Missing a period between "pcm" and "format"?

Missing after signature after re-reading it myself.

>
>> @@ -130,20 +161,24 @@ static int wsaud_read_packet(AVFormatContext *s,
>>                               AVPacket *pkt)
>>  {
>>      AVIOContext *pb = s->pb;
>> +    AUDDemuxContext *aud = s->priv_data;
>>      unsigned char preamble[AUD_CHUNK_PREAMBLE_SIZE];
>> -    unsigned int chunk_size;
>> +    unsigned int chunk_size, bytes_per_sample;
>>      int ret = 0;
>>      AVStream *st = s->streams[0];
>>  
>> -    if (avio_read(pb, preamble, AUD_CHUNK_PREAMBLE_SIZE) !=
>> -        AUD_CHUNK_PREAMBLE_SIZE)
>> -        return AVERROR(EIO);
>> +    /* AUD files don't store PCM audio in chunks */
>> +    if (st->codecpar->codec_id != AV_CODEC_ID_PCM_S16LE) {
>
>What about AV_CODEC_ID_PCM_U8?

Good catch, I don't think any actually exist in the wild, but I have supported
the possibility in wsaud_read_header and from looking at the audio engine it
looks to support it in theory.

>
>A sample + FATE test for this would be nice

Some guidance on where to start for that would be most welcome. I have short
examples from Blade Runner that could be used but wouldn't distributing them
violate copyright?

-- 
Aidan Richmond