[FFmpeg-devel] [PATCH 2/3] avcodec/rawdec: for 16-bit pix fmts, shift pixels when bits_per_coded_sample < 16

[Michael Niedermayer]

On Sun, Feb 23, 2014 at 12:18:42PM +1100, Peter Ross wrote:
> Signed-off-by: Peter Ross <pross at xvid.org>
> ---
>  libavcodec/rawdec.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/libavcodec/rawdec.c b/libavcodec/rawdec.c
> index e1682e3..5448b47 100644
> --- a/libavcodec/rawdec.c
> +++ b/libavcodec/rawdec.c
> @@ -41,6 +41,7 @@ typedef struct RawVideoContext {
>      int flip;
>      int is_2_4_bpp; // 2 or 4 bpp raw in avi/mov
>      int is_yuv2;
> +    int is_lt_16bpp; // 16bpp pixfmt and bits_per_coded_sample < 16
>      int tff;
>  } RawVideoContext;
>  
> @@ -142,6 +143,7 @@ static av_cold int raw_init_decoder(AVCodecContext *avctx)
>                                                   FFALIGN(avctx->width, 16),
>                                                   avctx->height);
>      } else {
> +        context->is_lt_16bpp = av_get_bits_per_pixel(desc) == 16 && avctx->bits_per_coded_sample && avctx->bits_per_coded_sample < 16;
>          context->frame_size = avpicture_get_size(avctx->pix_fmt, avctx->width,
>                                                   avctx->height);
>      }
> @@ -175,7 +177,7 @@ static int raw_decode(AVCodecContext *avctx, void *data, int *got_frame,
>      int buf_size                   = avpkt->size;
>      int linesize_align             = 4;
>      int res, len;
> -    int need_copy                  = !avpkt->buf || context->is_2_4_bpp || context->is_yuv2;
> +    int need_copy                  = !avpkt->buf || context->is_2_4_bpp || context->is_yuv2 || context->is_lt_16bpp;
>  
>      AVFrame   *frame   = data;
>      AVPicture *picture = data;

> @@ -240,6 +242,19 @@ static int raw_decode(AVCodecContext *avctx, void *data, int *got_frame,
>          return AVERROR(EINVAL);
>      }
>  
> +    if (context->is_lt_16bpp) {
> +        int i;
> +        uint8_t *dst = frame->buf[0]->data;
> +        if (desc->flags & AV_PIX_FMT_FLAG_BE) {
> +            for (i = 0; i + 1 < buf_size; i += 2)
> +                AV_WB16(dst + i, AV_RB16(buf + i) << (16 - avctx->bits_per_coded_sample));
> +        } else {
> +            for (i = 0; i + 1 < buf_size; i += 2)
> +                AV_WL16(dst + i, AV_RL16(buf + i) << (16 - avctx->bits_per_coded_sample));
> +        }
> +        buf = dst;
> +    }

iam not sure if this place or swscale would be optimal for this but
applied

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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