[FFmpeg-devel] [PATCH] avcodec/jpeglsdec: Don't allocate+free JPEGLSState for every frame

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Fri Apr 16 14:09:01 EEST 2021


Andreas Rheinhardt:
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
>  libavcodec/jpeglsdec.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/libavcodec/jpeglsdec.c b/libavcodec/jpeglsdec.c
> index 69980eaa49..92df81600b 100644
> --- a/libavcodec/jpeglsdec.c
> +++ b/libavcodec/jpeglsdec.c
> @@ -45,6 +45,11 @@
>   */
>  //#define JLS_BROKEN
>  
> +typedef struct JpegLSDecodeContext {
> +    MJpegDecodeContext mjpeg;
> +    JLSState state;
> +} JpegLSDecodeContext;
> +
>  /**
>   * Decode LSE block with initialization parameters
>   */
> @@ -350,7 +355,7 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
>  {
>      int i, t = 0;
>      uint8_t *zero, *last, *cur;
> -    JLSState *state;
> +    JLSState *const state = &((JpegLSDecodeContext*)s)->state;
>      int off = 0, stride = 1, width, shift, ret = 0;
>      int decoded_height = 0;
>  
> @@ -360,12 +365,8 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
>      last = zero;
>      cur  = s->picture_ptr->data[0];
>  
> -    state = av_mallocz(sizeof(JLSState));
> -    if (!state) {
> -        av_free(zero);
> -        return AVERROR(ENOMEM);
> -    }
>      /* initialize JPEG-LS state from JPEG parameters */
> +    memset(state, 0, sizeof(*state));
>      state->near   = near;
>      state->bpp    = (s->bits < 2) ? 2 : s->bits;
>      state->maxval = s->maxval;
> @@ -537,7 +538,6 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,
>      }
>  
>  end:
> -    av_free(state);
>      av_free(zero);
>  
>      return ret;
> @@ -548,7 +548,7 @@ AVCodec ff_jpegls_decoder = {
>      .long_name      = NULL_IF_CONFIG_SMALL("JPEG-LS"),
>      .type           = AVMEDIA_TYPE_VIDEO,
>      .id             = AV_CODEC_ID_JPEGLS,
> -    .priv_data_size = sizeof(MJpegDecodeContext),
> +    .priv_data_size = sizeof(JpegLSDecodeContext),
>      .init           = ff_mjpeg_decode_init,
>      .close          = ff_mjpeg_decode_end,
>      .receive_frame  = ff_mjpeg_receive_frame,
> 
Will apply tomorrow unless there are objections.

- Andreas



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