[FFmpeg-devel] [PATCH v3 1/4] avcodec/libjxldec: use internal AVFrame as buffered space

James Almer jamrial at gmail.com
Sat Jun 24 14:49:22 EEST 2023


On 6/24/2023 1:38 AM, Leo Izen wrote:
> Before this commit, the decoder erroneously assumes that the AVFrame
> passed to the receive_frame is the same one each time. Now it keeps an
> internal AVFrame to write into, and copies it over when it's done.
> ---
>   libavcodec/libjxldec.c | 40 +++++++++++++++++++++++-----------------
>   1 file changed, 23 insertions(+), 17 deletions(-)
> 
> diff --git a/libavcodec/libjxldec.c b/libavcodec/libjxldec.c
> index 50417bcb02..cea7ea0d3b 100644
> --- a/libavcodec/libjxldec.c
> +++ b/libavcodec/libjxldec.c
> @@ -58,6 +58,7 @@ typedef struct LibJxlDecodeContext {
>       int64_t frame_duration;
>       int prev_is_last;
>       AVRational timebase;
> +    AVFrame *frame;
>   } LibJxlDecodeContext;
>   
>   static int libjxl_init_jxl_decoder(AVCodecContext *avctx)
> @@ -104,6 +105,9 @@ static av_cold int libjxl_decode_init(AVCodecContext *avctx)
>   
>       ctx->avpkt = avctx->internal->in_pkt;
>       ctx->pts = 0;
> +    ctx->frame = av_frame_alloc();
> +    if (!ctx->frame)
> +        return AVERROR(ENOMEM);
>   
>       return libjxl_init_jxl_decoder(avctx);
>   }
> @@ -351,10 +355,12 @@ static int libjxl_receive_frame(AVCodecContext *avctx, AVFrame *frame)
>           size_t remaining;
>   
>           if (!pkt->size) {
> +            av_log(avctx, AV_LOG_DEBUG, "Fetching new packet\n");
>               av_packet_unref(pkt);
>               ret = ff_decode_get_packet(avctx, pkt);
>               if (ret < 0 && ret != AVERROR_EOF)
>                   return ret;
> +            av_log(avctx, AV_LOG_DEBUG, "Fetched packet of size: %d\n", pkt->size);
>               if (!pkt->size) {
>                   /* jret set by the last iteration of the loop */
>                   if (jret == JXL_DEC_NEED_MORE_INPUT) {
> @@ -389,10 +395,6 @@ static int libjxl_receive_frame(AVCodecContext *avctx, AVFrame *frame)
>               return AVERROR_INVALIDDATA;
>           case JXL_DEC_NEED_MORE_INPUT:
>               av_log(avctx, AV_LOG_DEBUG, "NEED_MORE_INPUT event emitted\n");
> -            if (!pkt->size) {
> -                av_packet_unref(pkt);
> -                return AVERROR(EAGAIN);
> -            }
>               continue;
>           case JXL_DEC_BASIC_INFO:
>               av_log(avctx, AV_LOG_DEBUG, "BASIC_INFO event emitted\n");
> @@ -421,16 +423,18 @@ static int libjxl_receive_frame(AVCodecContext *avctx, AVFrame *frame)
>               continue;
>           case JXL_DEC_COLOR_ENCODING:
>               av_log(avctx, AV_LOG_DEBUG, "COLOR_ENCODING event emitted\n");
> -            if ((ret = libjxl_color_encoding_event(avctx, frame)) < 0)
> +            if ((ret = libjxl_color_encoding_event(avctx, ctx->frame)) < 0)
>                   return ret;
>               continue;
>           case JXL_DEC_NEED_IMAGE_OUT_BUFFER:
>               av_log(avctx, AV_LOG_DEBUG, "NEED_IMAGE_OUT_BUFFER event emitted\n");
> -            if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
> +            ret = ff_get_buffer(avctx, ctx->frame, 0);
> +            if (ret < 0)
>                   return ret;
> -            ctx->jxl_pixfmt.align = frame->linesize[0];
> -            if (JxlDecoderSetImageOutBuffer(ctx->decoder, &ctx->jxl_pixfmt, frame->data[0], frame->buf[0]->size)
> -                != JXL_DEC_SUCCESS) {
> +            ctx->jxl_pixfmt.align = ctx->frame->linesize[0];
> +            if (JxlDecoderSetImageOutBuffer(ctx->decoder, &ctx->jxl_pixfmt,
> +                    ctx->frame->data[0], ctx->frame->buf[0]->size)
> +                    != JXL_DEC_SUCCESS) {
>                   av_log(avctx, AV_LOG_ERROR, "Bad libjxl dec need image out buffer event\n");
>                   return AVERROR_EXTERNAL;
>               }
> @@ -444,8 +448,8 @@ static int libjxl_receive_frame(AVCodecContext *avctx, AVFrame *frame)
>           case JXL_DEC_FRAME:
>               av_log(avctx, AV_LOG_DEBUG, "FRAME event emitted\n");
>               if (!ctx->basic_info.have_animation || ctx->prev_is_last) {
> -                frame->pict_type = AV_PICTURE_TYPE_I;
> -                frame->flags |= AV_FRAME_FLAG_KEY;
> +                ctx->frame->pict_type = AV_PICTURE_TYPE_I;
> +                ctx->frame->flags |= AV_FRAME_FLAG_KEY;
>               }
>               if (ctx->basic_info.have_animation) {
>                   JxlFrameHeader header;
> @@ -464,20 +468,21 @@ static int libjxl_receive_frame(AVCodecContext *avctx, AVFrame *frame)
>               /* full image is one frame, even if animated */
>               av_log(avctx, AV_LOG_DEBUG, "FULL_IMAGE event emitted\n");
>               if (ctx->iccp) {
> -                AVFrameSideData *sd = av_frame_new_side_data_from_buf(frame, AV_FRAME_DATA_ICC_PROFILE, ctx->iccp);
> +                AVFrameSideData *sd = av_frame_new_side_data_from_buf(ctx->frame, AV_FRAME_DATA_ICC_PROFILE, ctx->iccp);
>                   if (!sd)
>                       return AVERROR(ENOMEM);
>                   /* ownership is transfered, and it is not ref-ed */
>                   ctx->iccp = NULL;
>               }
>               if (avctx->pkt_timebase.num) {
> -                frame->pts = av_rescale_q(ctx->pts, ctx->timebase, avctx->pkt_timebase);
> -                frame->duration = av_rescale_q(ctx->frame_duration, ctx->timebase, avctx->pkt_timebase);
> +                ctx->frame->pts = av_rescale_q(ctx->pts, ctx->timebase, avctx->pkt_timebase);
> +                ctx->frame->duration = av_rescale_q(ctx->frame_duration, ctx->timebase, avctx->pkt_timebase);
>               } else {
> -                frame->pts = ctx->pts;
> -                frame->duration = ctx->frame_duration;
> +                ctx->frame->pts = ctx->pts;
> +                ctx->frame->duration = ctx->frame_duration;
>               }
>               ctx->pts += ctx->frame_duration;
> +            av_frame_move_ref(frame, ctx->frame);
>               return 0;
>           case JXL_DEC_SUCCESS:
>               av_log(avctx, AV_LOG_DEBUG, "SUCCESS event emitted\n");
> @@ -508,6 +513,7 @@ static av_cold int libjxl_decode_close(AVCodecContext *avctx)
>           JxlDecoderDestroy(ctx->decoder);
>       ctx->decoder = NULL;
>       av_buffer_unref(&ctx->iccp);
> +    av_frame_free(&ctx->frame);
>   
>       return 0;
>   }
> @@ -521,7 +527,7 @@ const FFCodec ff_libjxl_decoder = {
>       .init             = libjxl_decode_init,
>       FF_CODEC_RECEIVE_FRAME_CB(libjxl_receive_frame),
>       .close            = libjxl_decode_close,
> -    .p.capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_OTHER_THREADS,

Why remove DR1? ff_get_buffer() is still called and user provided 
buffers should still work fine.

> +    .p.capabilities   = AV_CODEC_CAP_OTHER_THREADS,
>       .caps_internal    = FF_CODEC_CAP_NOT_INIT_THREADSAFE |
>                           FF_CODEC_CAP_AUTO_THREADS | FF_CODEC_CAP_INIT_CLEANUP |
>                           FF_CODEC_CAP_ICC_PROFILES,


More information about the ffmpeg-devel mailing list