[FFmpeg-devel] [PATCH 7/8] avcodec/qtrle: return last frame even if unchanged

[Paul B Mahol]

On Mon, Aug 12, 2019 at 9:19 PM Michael Niedermayer <michael at niedermayer.cc>
wrote:

> Fixes: Ticket7880
>
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavcodec/qtrle.c        | 44 +++++++++++++++++++++++++++++++++++----
>  tests/ref/fate/qtrle-8bit |  1 +
>  2 files changed, 41 insertions(+), 4 deletions(-)
>
> diff --git a/libavcodec/qtrle.c b/libavcodec/qtrle.c
> index 2c29547e5a..ab620cdb55 100644
> --- a/libavcodec/qtrle.c
> +++ b/libavcodec/qtrle.c
> @@ -45,6 +45,8 @@ typedef struct QtrleContext {
>
>      GetByteContext g;
>      uint32_t pal[256];
> +    int need_flush;
> +    AVPacket flush_pkt;
>  } QtrleContext;
>
>  #define CHECK_PIXEL_PTR(n)
>             \
> @@ -444,6 +446,12 @@ static av_cold int qtrle_decode_init(AVCodecContext
> *avctx)
>      return 0;
>  }
>
> +static void qtrle_flush(AVCodecContext *avctx){
> +    QtrleContext *s = avctx->priv_data;
> +
> +    s->need_flush = 0;
> +}
> +
>  static int qtrle_decode_frame(AVCodecContext *avctx,
>                                void *data, int *got_frame,
>                                AVPacket *avpkt)
> @@ -454,11 +462,33 @@ static int qtrle_decode_frame(AVCodecContext *avctx,
>      int has_palette = 0;
>      int ret, size;
>
> +    if (!avpkt->data) {
> +        if (s->need_flush) {
> +            s->need_flush = 0;
> +            if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
> +                return ret;
> +            s->frame->pkt_pos      = s->flush_pkt.pos;
> +            s->frame->pkt_duration = s->flush_pkt.duration;
> +            s->frame->pkt_dts      = s->flush_pkt.dts;
> +            s->frame->pkt_pts      =
> +            s->frame->pts          = s->flush_pkt.pts;
> +            if ((ret = av_frame_ref(data, s->frame)) < 0)
> +                return ret;
> +            *got_frame = 1;
> +        }
> +        return 0;
> +    }
> +    s->flush_pkt = *avpkt;
> +    s->frame->pkt_dts = s->flush_pkt.dts;
> +
>      bytestream2_init(&s->g, avpkt->data, avpkt->size);
>
>      /* check if this frame is even supposed to change */
> -    if (avpkt->size < 8)
> +    if (avpkt->size < 8) {
> +        s->need_flush = 1;
>          return avpkt->size;
> +    }
> +    s->need_flush = 0;
>
>      /* start after the chunk size */
>      size = bytestream2_get_be32(&s->g) & 0x3FFFFFFF;
> @@ -471,14 +501,18 @@ static int qtrle_decode_frame(AVCodecContext *avctx,
>
>      /* if a header is present, fetch additional decoding parameters */
>      if (header & 0x0008) {
> -        if (avpkt->size < 14)
> +        if (avpkt->size < 14) {
> +            s->need_flush = 1;
>              return avpkt->size;
> +        }
>          start_line = bytestream2_get_be16(&s->g);
>          bytestream2_skip(&s->g, 2);
>          height     = bytestream2_get_be16(&s->g);
>          bytestream2_skip(&s->g, 2);
> -        if (height > s->avctx->height - start_line)
> +        if (height > s->avctx->height - start_line) {
> +            s->need_flush = 1;
>              return avpkt->size;
> +        }
>      } else {
>          start_line = 0;
>          height     = s->avctx->height;
> @@ -572,5 +606,7 @@ AVCodec ff_qtrle_decoder = {
>      .init           = qtrle_decode_init,
>      .close          = qtrle_decode_end,
>      .decode         = qtrle_decode_frame,
> -    .capabilities   = AV_CODEC_CAP_DR1,
> +    .flush          = qtrle_flush,
> +    .caps_internal  = FF_CODEC_CAP_SETS_PKT_DTS,
> +    .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
>  };
> diff --git a/tests/ref/fate/qtrle-8bit b/tests/ref/fate/qtrle-8bit
> index 27bb8aad71..39a03b7b6c 100644
> --- a/tests/ref/fate/qtrle-8bit
> +++ b/tests/ref/fate/qtrle-8bit
> @@ -61,3 +61,4 @@
>  0,        160,        160,        1,   921600, 0xcfd6ad2b
>  0,        163,        163,        1,   921600, 0x3b372379
>  0,        165,        165,        1,   921600, 0x36f245f5
> +0,        166,        166,        1,   921600, 0x36f245f5
> --
>


I dislike this hack and I'm for removing hack that removes dupe frames all
together.

2.22.0
>
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