[FFmpeg-devel] [PATCH 2/3 v2] avcodec/encode: restructure the old encode API

[James Almer]

On 3/26/2020 4:42 PM, Anton Khirnov wrote:
> Quoting James Almer (2020-03-26 20:28:12)
>> On 3/26/2020 5:57 AM, Anton Khirnov wrote:
>>> Quoting James Almer (2020-03-16 22:30:01)
>>>> Following the same logic as 061a0c14bb, this commit turns the old encode API
>>>> into a wrapper for the new one.
>>>>
>>>> Signed-off-by: James Almer <jamrial at gmail.com>
>>>> ---
>>>> This could be squashed with the previous commit, like it was done in 061a0c14bb,
>>>> but i figured it would be easier to review this way.
>>>>
>>>>  libavcodec/encode.c   | 364 +++++++++++++-----------------------------
>>>>  libavcodec/internal.h |   1 +
>>>>  libavcodec/utils.c    |   8 +
>>>>  3 files changed, 116 insertions(+), 257 deletions(-)
>>>>
>>>> diff --git a/libavcodec/encode.c b/libavcodec/encode.c
>>>> index cdea1c6c1e..0fdb9e2df2 100644
>>>> --- a/libavcodec/encode.c
>>>> +++ b/libavcodec/encode.c
>>>> @@ -610,3 +361,102 @@ int attribute_align_arg avcodec_receive_packet(AVCodecContext *avctx, AVPacket *
>>>>  
>>>>      return 0;
>>>>  }
>>>> +
>>>> +static int compat_encode(AVCodecContext *avctx, AVPacket *avpkt,
>>>> +                         int *got_packet, const AVFrame *frame)
>>>> +{
>>>> +    AVCodecInternal *avci = avctx->internal;
>>>> +    AVPacket user_pkt;
>>>> +    int ret;
>>>> +
>>>> +    *got_packet = 0;
>>>> +
>>>> +    if (frame && avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
>>>> +        if (frame->format == AV_PIX_FMT_NONE)
>>>> +            av_log(avctx, AV_LOG_WARNING, "AVFrame.format is not set\n");
>>>> +        if (frame->width == 0 || frame->height == 0)
>>>> +            av_log(avctx, AV_LOG_WARNING, "AVFrame.width or height is not set\n");
>>>> +    }
>>>> +
>>>> +    ret = avcodec_send_frame(avctx, frame);
>>>> +    if (ret == AVERROR_EOF)
>>>> +        ret = 0;
>>>> +    else if (ret == AVERROR(EAGAIN)) {
>>>> +        /* we fully drain all the output in each encode call, so this should not
>>>> +         * ever happen */
>>>> +        return AVERROR_BUG;
>>>> +    } else if (ret < 0)
>>>> +        return ret;
>>>> +
>>>> +    av_packet_move_ref(&user_pkt, avpkt);
>>>> +    while (ret >= 0) {
>>>> +        ret = avcodec_receive_packet(avctx, avpkt);
>>>> +        if (ret < 0) {
>>>> +            if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
>>>> +                ret = 0;
>>>> +            goto finish;
>>>> +        }
>>>> +
>>>> +        if (avpkt != avci->compat_encode_packet) {
>>>> +            if (avpkt->data && user_pkt.data) {
>>>> +                if (user_pkt.size >= avpkt->size) {
>>>> +                    memcpy(user_pkt.data, avpkt->data, avpkt->size);
>>>> +                    av_buffer_unref(&avpkt->buf);
>>>> +                    avpkt->buf  = user_pkt.buf;
>>>> +                    avpkt->data = user_pkt.data;
>>>> +                    av_init_packet(&user_pkt);
>>>> +                } else {
>>>> +                    av_log(avctx, AV_LOG_ERROR, "Provided packet is too small, needs to be %d\n", avpkt->size);
>>>> +                    ret = AVERROR(EINVAL);
>>>> +                    goto finish;
>>>
>>> Shouldn't the packet be unreffed somewhere in this block?
>>
>> Yeah. Fixed locally.
>>
>>>
>>>> +                }
>>>> +            }
>>>> +
>>>> +            *got_packet = 1;
>>>> +            avpkt = avci->compat_encode_packet;
>>>> +        } else {
>>>> +            if (!avci->compat_decode_warned) {
>>>> +                av_log(avctx, AV_LOG_WARNING, "The deprecated avcodec_encode_* "
>>>> +                       "API cannot return all the packets for this encoder. "
>>>> +                       "Some packets will be dropped. Update your code to the "
>>>> +                       "new encoding API to fix this.\n");
>>>> +                avci->compat_decode_warned = 1;
>>>> +            }
>>>
>>> Same.
>>
>> avpkt is avci->compat_encode_packet in this block. It will either be
>> unreffed next time avcodec_receive_packet() is called with it, or by
>> avcodec_close(). No need to unref it here explicitly, but i can do it if
>> you prefer that.
> 
> I think it's better not to leave data we're not going to use just lying
> around for no reason. So yeah, I'd prefer it to be unreffed here.

Ok, added and the updated set sent.