[FFmpeg-devel] [PATCH] avcodec/v4l2_m2m_enc: Adapt to the new internal encode API

[James Almer]

On 3/7/2020 9:23 PM, Andriy Gelman wrote:
> From: Andriy Gelman <andriy.gelman at gmail.com>
> 
> Should be squashed with:
> http://ffmpeg.org/pipermail/ffmpeg-devel/2020-February/257735.html
> 
> Signed-off-by: Andriy Gelman <andriy.gelman at gmail.com>
> ---
>  libavcodec/v4l2_m2m.c     |  9 ++++++++-
>  libavcodec/v4l2_m2m.h     |  6 +++++-
>  libavcodec/v4l2_m2m_dec.c |  2 +-
>  libavcodec/v4l2_m2m_enc.c | 17 +++++++++++++++--
>  4 files changed, 29 insertions(+), 5 deletions(-)
> 
> diff --git a/libavcodec/v4l2_m2m.c b/libavcodec/v4l2_m2m.c
> index 2d21f910bcc..1799837fb9f 100644
> --- a/libavcodec/v4l2_m2m.c
> +++ b/libavcodec/v4l2_m2m.c
> @@ -329,6 +329,7 @@ static void v4l2_m2m_destroy_context(void *opaque, uint8_t *context)
>      sem_destroy(&s->refsync);
>  
>      close(s->fd);
> +    av_frame_free(&s->frame);
>  
>      av_free(s);
>  }
> @@ -394,7 +395,7 @@ int ff_v4l2_m2m_codec_init(V4L2m2mPriv *priv)
>      return v4l2_configure_contexts(s);
>  }
>  
> -int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s)
> +int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, int is_encoder, V4L2m2mContext **s)
>  {
>      *s = av_mallocz(sizeof(V4L2m2mContext));
>      if (!*s)
> @@ -417,5 +418,11 @@ int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s)
>      priv->context->self_ref = priv->context_ref;
>      priv->context->fd = -1;
>  
> +    if (is_encoder) {
> +        priv->context->frame = av_frame_alloc();
> +        if (!priv->context->frame)
> +            return AVERROR(ENOMEM);
> +    }
> +
>      return 0;
>  }
> diff --git a/libavcodec/v4l2_m2m.h b/libavcodec/v4l2_m2m.h
> index 456281f48c5..5d6106224dd 100644
> --- a/libavcodec/v4l2_m2m.h
> +++ b/libavcodec/v4l2_m2m.h
> @@ -58,6 +58,9 @@ typedef struct V4L2m2mContext {
>      int draining;
>      AVPacket buf_pkt;
>  
> +    /* Reference to a frame. Only used during encoding */
> +    AVFrame *frame;
> +
>      /* Reference to self; only valid while codec is active. */
>      AVBufferRef *self_ref;
>  
> @@ -79,11 +82,12 @@ typedef struct V4L2m2mPriv {
>   * Allocate a new context and references for a V4L2 M2M instance.
>   *
>   * @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder.
> + * @param[in] is_encoder Whether the context is for encoder/decoder
>   * @param[out] ctx The V4L2m2mContext.
>   *
>   * @returns 0 in success, a negative error code otherwise.
>   */
> -int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s);
> +int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, int is_encoder, V4L2m2mContext **s);
>  
>  
>  /**
> diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c
> index d666edffe46..7c7ac2de8c5 100644
> --- a/libavcodec/v4l2_m2m_dec.c
> +++ b/libavcodec/v4l2_m2m_dec.c
> @@ -181,7 +181,7 @@ static av_cold int v4l2_decode_init(AVCodecContext *avctx)
>      V4L2m2mPriv *priv = avctx->priv_data;
>      int ret;
>  
> -    ret = ff_v4l2_m2m_create_context(priv, &s);
> +    ret = ff_v4l2_m2m_create_context(priv, !av_codec_is_decoder(avctx->codec), &s);
>      if (ret < 0)
>          return ret;
>  
> diff --git a/libavcodec/v4l2_m2m_enc.c b/libavcodec/v4l2_m2m_enc.c
> index c9f1741bfd0..22b0cbd27ac 100644
> --- a/libavcodec/v4l2_m2m_enc.c
> +++ b/libavcodec/v4l2_m2m_enc.c
> @@ -24,6 +24,7 @@
>  #include <linux/videodev2.h>
>  #include <sys/ioctl.h>
>  #include <search.h>
> +#include "encode.h"
>  #include "libavcodec/avcodec.h"
>  #include "libavutil/pixdesc.h"
>  #include "libavutil/pixfmt.h"
> @@ -259,11 +260,24 @@ static int v4l2_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
>      V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context;
>      V4L2Context *const capture = &s->capture;
>      V4L2Context *const output = &s->output;
> +    AVFrame *frame = s->frame;
>      int ret;
>  
>      if (s->draining)
>          goto dequeue;
>  
> +    ret = ff_encode_get_frame(avctx, frame);
> +    if (ret < 0 && ret != AVERROR_EOF)
> +        return ret;
> +
> +    if (ret == AVERROR_EOF)
> +        frame = NULL;
> +
> +    ret = v4l2_send_frame(avctx, frame);

What happens if ff_encode_get_frame() returns AVERROR(EAGAIN)? I don't
think ff_v4l2_context_enqueue_frame() is meant to receive empty,
non-NULL frames.

> +    av_frame_unref(frame);
> +    if (ret < 0)
> +        return ret;
> +
>      if (!output->streamon) {
>          ret = ff_v4l2_context_set_status(output, VIDIOC_STREAMON);
>          if (ret) {
> @@ -293,7 +307,7 @@ static av_cold int v4l2_encode_init(AVCodecContext *avctx)
>      uint32_t v4l2_fmt_output;
>      int ret;
>  
> -    ret = ff_v4l2_m2m_create_context(priv, &s);
> +    ret = ff_v4l2_m2m_create_context(priv, !av_codec_is_decoder(avctx->codec), &s);
>      if (ret < 0)
>          return ret;
>  
> @@ -367,7 +381,6 @@ static const AVOption options[] = {
>          .priv_data_size = sizeof(V4L2m2mPriv), \
>          .priv_class     = &v4l2_m2m_ ## NAME ##_enc_class, \
>          .init           = v4l2_encode_init, \
> -        .send_frame     = v4l2_send_frame, \
>          .receive_packet = v4l2_receive_packet, \
>          .close          = v4l2_encode_close, \
>          .capabilities   = AV_CODEC_CAP_HARDWARE | AV_CODEC_CAP_DELAY, \
>