[FFmpeg-devel] [PATCHv4] avcodec: Add librav1e encoder

[Derek Buitenhuis]

On 09/07/2019 22:06, James Almer wrote:
>> @@ -3174,6 +3176,7 @@ libopenmpt_demuxer_deps="libopenmpt"
>>  libopus_decoder_deps="libopus"
>>  libopus_encoder_deps="libopus"
>>  libopus_encoder_select="audio_frame_queue"
>> +librav1e_encoder_deps="librav1e"
> 
> Needs to enable extract_extradata_bsf with a _select line as well.

Fixed locally.

>> +    if (ctx->tiles >= 0) {
>> +        rret = rav1e_config_parse_int(cfg, "tiles", ctx->speed);
> 
> ctx->tiles

Fixed locally.

> 
> Also, it may be a good idea to instead look into making the "tiles"
> option parsing code in libaomenc shared and reuse it here, so it's
> consistent between encoders. With it you can pass a Cols x Rows string
> using the AV_OPT_TYPE_IMAGE_SIZE AVOption type and derive values you can
> then map to rav1e's tile_rows_log2 and tile_cols_log2 options.

Heavily disagree. rav1e has its own 'tiles' option that determines the right
cols/rows to use for a reason, and I will not be emulating libaomenc's algo
instead of using the one provided by rav1e. It's confusing at best (since
it goes against the rav1e API, and makes the official CLI and ffmpeg work
differently).

> In the meantime, you can define tile-columns and tile-rows AVOptions and
> directly map them to the aforementioned rav1e options.

Why? What's the use-case? "Being the same as libaomenc" is not a good use case.

>> +    case RA_ENCODER_STATUS_ENCODED:
>> +        if (avctx->internal->draining)
>> +            goto retry;
>> +        return AVERROR(EAGAIN);
> 
> Is rav1e_send_frame() guaranteed to not return
> RA_ENCODER_STATUS_ENOUGH_DATA if called right after
> rav1e_receive_packet() returned RA_ENCODER_STATUS_ENCODED?
> In other words, if it encoded a frame but didn't return it, is it safe
> to assume its buffers are not full and will not reject new data passed
> to it?

rav1e, in fact, never returns this error. I need to check what the
guarantee is, though - I'm not sure what the future plans are.

> If not, then we would have to do goto retry here unconditionally,
> draining or not. The doxy for avcodec_receive_packet and
> avcodec_send_frame state that when one returns EAGAIN, the other is
> guaranteed to return something else.

[...]

- Derek