On Fri, Jul 17, 2015 at 2:07 AM, Luca Barbato <[email protected]> wrote: > Enjoy some cache locality and use less threads. > About 5x speedup (from 60ms to 12ms to decode a 4k frame). > --- > libavcodec/hap.h | 2 ++ > libavcodec/hapdec.c | 33 +++++++++++++++++++++++++-------- > 2 files changed, 27 insertions(+), 8 deletions(-) > > diff --git a/libavcodec/hap.h b/libavcodec/hap.h > index 1250a6f..75299fd 100644 > --- a/libavcodec/hap.h > +++ b/libavcodec/hap.h > @@ -46,6 +46,8 @@ 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 */ > + > /* Pointer to the selected compress or decompress function */ > int (*tex_fun)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block); > } HapContext; > diff --git a/libavcodec/hapdec.c b/libavcodec/hapdec.c > index 72db9f4..5133a51 100644 > --- a/libavcodec/hapdec.c > +++ b/libavcodec/hapdec.c > @@ -137,16 +137,30 @@ static int setup_texture(AVCodecContext *avctx, size_t > length) > } > > static int decompress_texture_thread(AVCodecContext *avctx, void *arg, > - int block_nb, int thread_nb) > + int slice, int thread_nb) > { > HapContext *ctx = avctx->priv_data; > AVFrame *frame = arg; > - int x = (TEXTURE_BLOCK_W * block_nb) % avctx->coded_width; > - int y = TEXTURE_BLOCK_H * (TEXTURE_BLOCK_W * block_nb / > avctx->coded_width); > - uint8_t *p = frame->data[0] + x * 4 + y * frame->linesize[0]; > - const uint8_t *d = ctx->tex_data + block_nb * ctx->tex_rat; > + const uint8_t *d = ctx->tex_data; > + int w_block = avctx->coded_width / TEXTURE_BLOCK_W; > + int x, y; > + int start_slice, end_slice; > + > + start_slice = slice * ctx->slice_size; > + end_slice = FFMIN(start_slice + ctx->slice_size, avctx->coded_height); > + > + start_slice /= TEXTURE_BLOCK_H; > + end_slice /= TEXTURE_BLOCK_H; > + > + for (y = start_slice; y < end_slice; y++) { > + uint8_t *p = frame->data[0] + y * frame->linesize[0] * > TEXTURE_BLOCK_H; > + int off = y * w_block; > + for (x = 0; x < w_block; x++) { > + ctx->tex_fun(p + x * 16, frame->linesize[0], > + d + (off + x) * ctx->tex_rat); > + } > + } > > - ctx->tex_fun(p, frame->linesize[0], d); > return 0; > } > > @@ -156,7 +170,10 @@ static int hap_decode(AVCodecContext *avctx, void *data, > HapContext *ctx = avctx->priv_data; > ThreadFrame tframe; > int ret, length; > - int blocks = avctx->coded_width * avctx->coded_height / (TEXTURE_BLOCK_W > * TEXTURE_BLOCK_H); > + 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); > > @@ -180,7 +197,7 @@ 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, > blocks); > + avctx->execute2(avctx, decompress_texture_thread, tframe.f, NULL, > slices); > > /* Frame is ready to be output */ > tframe.f->pict_type = AV_PICTURE_TYPE_I;
I don't see anything wrong with this approach. Tom, have you got any comments? -- Vittorio _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
