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hap: Fix slice size computation

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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.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This commit is contained in:
Tom Butterworth 2015-07-23 00:01:01 +01:00 committed by Luca Barbato
parent ebe8b5d947
commit ae5a8dca67
2 changed files with 18 additions and 10 deletions
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2
libavcodec/hap.h
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@ -46,7 +46,7 @@ typedef struct HapContext {
uint8_t *snappied; /* Buffer interacting with snappy */
size_t max_snappy; /* Maximum compressed size for snappy buffer */
int slice_size; /* Optimal slice size */
int slice_count; /* Number of slices for threaded operations */
/* Pointer to the selected compress or decompress function */
int (*tex_fun)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block);

26
libavcodec/hapdec.c
View File

@ -143,14 +143,23 @@ static int decompress_texture_thread(AVCodecContext *avctx, void *arg,
AVFrame *frame = arg;
const uint8_t *d = ctx->tex_data;
int w_block = avctx->coded_width / TEXTURE_BLOCK_W;
int h_block = avctx->coded_height / TEXTURE_BLOCK_H;
int x, y;
int start_slice, end_slice;
int base_blocks_per_slice = h_block / ctx->slice_count;
int remainder_blocks = h_block % ctx->slice_count;
start_slice = slice * ctx->slice_size;
end_slice = FFMIN(start_slice + ctx->slice_size, avctx->coded_height);
/* When the frame height (in blocks) doesn't divide evenly between the
* number of slices, spread the remaining blocks evenly between the first
* operations */
start_slice = slice * base_blocks_per_slice;
/* Add any extra blocks (one per slice) that have been added before this slice */
start_slice += FFMIN(slice, remainder_blocks);
start_slice /= TEXTURE_BLOCK_H;
end_slice /= TEXTURE_BLOCK_H;
end_slice = start_slice + base_blocks_per_slice;
/* Add an extra block if there are still remainder blocks to be accounted for */
if (slice < remainder_blocks)
end_slice++;
for (y = start_slice; y < end_slice; y++) {
uint8_t *p = frame->data[0] + y * frame->linesize[0] * TEXTURE_BLOCK_H;
@ -170,10 +179,6 @@ static int hap_decode(AVCodecContext *avctx, void *data,
HapContext *ctx = avctx->priv_data;
ThreadFrame tframe;
int ret, length;
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);
@ -197,7 +202,7 @@ static int hap_decode(AVCodecContext *avctx, void *data,
ff_thread_finish_setup(avctx);
/* 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;
@ -227,6 +232,9 @@ static av_cold int hap_init(AVCodecContext *avctx)
ff_texturedsp_init(&ctx->dxtc);
ctx->slice_count = av_clip(avctx->thread_count, 1,
avctx->coded_height / TEXTURE_BLOCK_H);
return 0;
}