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

[Paul B Mahol]

On Wed, Aug 14, 2019 at 6:04 PM Paul B Mahol <onemda at gmail.com> wrote:

>
>
> 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.
>

To all codecs that exhibit it. Not just qtrle....


> 2.22.0
>>
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>
>