[FFmpeg-devel] [PATCH] avcodec: add ATRAC Advanced Lossless decoders

[Paul B Mahol]

On 1/31/17, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Sun, Jan 29, 2017 at 06:39:21PM +0100, Paul B Mahol wrote:
>> Only lossy part is decoded for now.
>>
>> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>> ---
> [...]
>>  static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
>>  {
>>      OMAContext *oc  = s->priv_data;
>> -    AVStream *st    = s->streams[0];
>> -    int packet_size = st->codecpar->block_align;
>> -    int byte_rate   = st->codecpar->bit_rate >> 3;
>> -    int64_t pos     = avio_tell(s->pb);
>> -    int ret         = av_get_packet(s->pb, pkt, packet_size);
>> -
>> -    if (ret < packet_size)
>> -        pkt->flags |= AV_PKT_FLAG_CORRUPT;
>> -
>> -    if (ret < 0)
>> -        return ret;
>> -    if (!ret)
>> -        return AVERROR_EOF;
>> -
>> -    pkt->stream_index = 0;
>> -
>> -    if (pos >= oc->content_start && byte_rate > 0) {
>> -        pkt->pts =
>> -        pkt->dts = av_rescale(pos - oc->content_start,
>> st->time_base.den,
>> -                              byte_rate * (int64_t)st->time_base.num);
>> -    }
>> -
>> -    if (oc->encrypted) {
>> -        /* previous unencrypted block saved in IV for
>> -         * the next packet (CBC mode) */
>> -        if (ret == packet_size)
>> -            av_des_crypt(oc->av_des, pkt->data, pkt->data,
>> -                         (packet_size >> 3), oc->iv, 1);
>> -        else
>> -            memset(oc->iv, 0, 8);
>> -    }
>> -
>> -    return ret;
>> +    return oc->read_packet(s, pkt);
>>  }
>
> moving this into read_packet() could be done in a seperate patch
>
>
>>
>>  static int oma_read_probe(AVProbeData *p)
>> @@ -491,8 +571,14 @@ static int oma_read_seek(struct AVFormatContext *s,
>>                           int stream_index, int64_t timestamp, int flags)
>>  {
>>      OMAContext *oc = s->priv_data;
>> -    int64_t err = ff_pcm_read_seek(s, stream_index, timestamp, flags);
>> +    AVStream *st = s->streams[0];
>> +    int64_t err;
>> +
>> +    if (st->codecpar->codec_id == AV_CODEC_ID_ATRAC3PAL ||
>> +        st->codecpar->codec_id == AV_CODEC_ID_ATRAC3AL)
>
>> +        return -1;
>
> should be a AVERROR code

This is not error, it makes seeking possible, using other error codes
is bad idea.

>
>
> thanks
>
> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Those who would give up essential Liberty, to purchase a little
> temporary Safety, deserve neither Liberty nor Safety -- Benjamin Franklin
>