On Wed, Jul 22, 2015 at 09:46:24PM +0100, Tom Butterworth wrote:
> A bug was introduced in 977105407cae55876041dddbf4ce0934cdd4cd6c whereby when
> frame height wasn't divisible by the number of threads, pixels would be
> omitted
> from the bottom rows during decode.
> ---
> libavcodec/hap.h | 1 +
> libavcodec/hapdec.c | 17 +++++++++++------
> 2 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/libavcodec/hap.h b/libavcodec/hap.h
> index 893b4c5..a46738e 100644
> --- a/libavcodec/hap.h
> +++ b/libavcodec/hap.h
> @@ -77,6 +77,7 @@ typedef struct HapContext {
>
> size_t max_snappy; /* Maximum compressed size for snappy buffer */
>
> + int slice_count; /* Number of slices for threaded operations */
> int slice_size; /* Optimal slice size */
>
> /* Pointer to the selected compress or decompress function */
> diff --git a/libavcodec/hapdec.c b/libavcodec/hapdec.c
> index c05d4c0..69a925d 100644
> --- a/libavcodec/hapdec.c
> +++ b/libavcodec/hapdec.c
> @@ -275,7 +275,12 @@ static int decompress_texture_thread(AVCodecContext
> *avctx, void *arg,
> int start_slice, end_slice;
>
> start_slice = slice * ctx->slice_size;
> - end_slice = FFMIN(start_slice + ctx->slice_size, avctx->coded_height);
> + /* If the frame height isn't divisible by the number of slices then the
> + * last slice must cover more rows than ctx->slice_size */
> + if (slice == ctx->slice_count - 1)
> + end_slice = avctx->coded_height;
> + else
> + end_slice = FFMIN(start_slice + ctx->slice_size,
> avctx->coded_height);
>
> start_slice /= TEXTURE_BLOCK_H;
> end_slice /= TEXTURE_BLOCK_H;
> @@ -298,10 +303,6 @@ static int hap_decode(AVCodecContext *avctx, void *data,
> HapContext *ctx = avctx->priv_data;
> ThreadFrame tframe;
> int ret, i;
> - int slices = FFMIN(avctx->thread_count,
> - avctx->coded_height / TEXTURE_BLOCK_H);
> -
> - ctx->slice_size = avctx->coded_height / slices;
>
> bytestream2_init(&ctx->gbc, avpkt->data, avpkt->size);
>
> @@ -340,7 +341,7 @@ static int hap_decode(AVCodecContext *avctx, void *data,
> }
>
> /* Use the decompress function on the texture, one block per thread */
> - avctx->execute2(avctx, decompress_texture_thread, tframe.f, NULL,
> slices);
> + avctx->execute2(avctx, decompress_texture_thread, tframe.f, NULL,
> ctx->slice_count);
>
> /* Frame is ready to be output */
> tframe.f->pict_type = AV_PICTURE_TYPE_I;
> @@ -391,6 +392,10 @@ static av_cold int hap_init(AVCodecContext *avctx)
> return AVERROR_DECODER_NOT_FOUND;
> }
>
> + ctx->slice_count = av_clip(avctx->thread_count, 1,
> + avctx->coded_height / TEXTURE_BLOCK_H);
> + ctx->slice_size = avctx->coded_height / ctx->slice_count;wont this potentially result in a last slice that could be alot larger than the other slices ? as in height= 248 threads=32 ctx->slice_count = 32 slice_size = 7 31 slices of height 7 and 1 of height 31 it might be better to use something like slice start = slice * height / slice_count if iam not missing something [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB I am the wisest man alive, for I know one thing, and that is that I know nothing. -- Socrates
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