[FFmpeg-devel] [FFmpeg-cvslog] avcodec/gif: enable encoding single gif image per frame

[Carl Eugen Hoyos]

2018-12-13 19:32 GMT+01:00, Paul B Mahol <git at videolan.org>:
> ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Dec 12
> 13:19:33 2018 +0100| [bb0984cc29e93e56506722fe0ce5c6d43b6d4326] | committer:
> Paul B Mahol
>
> avcodec/gif: enable encoding single gif image per frame
>
> Unbreaks gif image2 muxer.
>
>> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bb0984cc29e93e56506722fe0ce5c6d43b6d4326
> ---
>
>  libavcodec/gif.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/libavcodec/gif.c b/libavcodec/gif.c
> index 408b7534da..67fc5a1bda 100644
> --- a/libavcodec/gif.c
> +++ b/libavcodec/gif.c
> @@ -51,6 +51,7 @@ typedef struct GIFContext {
>      int is_first_frame;
>      AVFrame *last_frame;
>      int flags;
> +    int image;
>      uint32_t palette[AVPALETTE_COUNT];  ///< local reference palette for
> !pal8
>      int palette_loaded;
>      int transparent_index;
> @@ -422,6 +423,9 @@ static int gif_encode_frame(AVCodecContext *avctx,
> AVPacket *pkt,
>      outbuf_ptr = pkt->data;
>      end        = pkt->data + pkt->size;
>
> +    if (s->image)
> +        s->is_first_frame = 1;
> +
>      if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
>          palette = (uint32_t*)pict->data[1];
>
> @@ -436,19 +440,22 @@ static int gif_encode_frame(AVCodecContext *avctx,
> AVPacket *pkt,
>
>      gif_image_write_image(avctx, &outbuf_ptr, end, palette,
>                            pict->data[0], pict->linesize[0], pkt);
> -    if (!s->last_frame) {
> +    if (!s->last_frame && !s->image) {
>          s->last_frame = av_frame_alloc();
>          if (!s->last_frame)
>              return AVERROR(ENOMEM);
>      }
>
> -    av_frame_unref(s->last_frame);
> -    ret = av_frame_ref(s->last_frame, (AVFrame*)pict);
> -    if (ret < 0)
> -        return ret;
> +    if (!s->image) {
> +        av_frame_unref(s->last_frame);
> +        ret = av_frame_ref(s->last_frame, (AVFrame*)pict);
> +        if (ret < 0)
> +            return ret;
> +    }
>
>      pkt->size   = outbuf_ptr - pkt->data;
> -    pkt->flags |= AV_PKT_FLAG_KEY;
> +    if (s->is_first_frame)
> +        pkt->flags |= AV_PKT_FLAG_KEY;
>      *got_packet = 1;
>
>      return 0;
> @@ -472,6 +479,7 @@ static const AVOption gif_options[] = {
>      { "gifflags", "set GIF flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64
> = GF_OFFSETTING|GF_TRANSDIFF}, 0, INT_MAX, FLAGS, "flags" },
>          { "offsetting", "enable picture offsetting", 0, AV_OPT_TYPE_CONST,
> {.i64=GF_OFFSETTING}, INT_MIN, INT_MAX, FLAGS, "flags" },
>          { "transdiff", "enable transparency detection between frames", 0,
> AV_OPT_TYPE_CONST, {.i64=GF_TRANSDIFF}, INT_MIN, INT_MAX, FLAGS, "flags" },
> +    { "gifimage", "enable encoding only images per frame", OFFSET(image),
> AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS, "flags" },

Would it not be possible to detect in the flush function that only one frame
was encoded and make the flag unnecessary?

Carl Eugen