[FFmpeg-cvslog] avcodec/hevcdec: Don't allocate redundant HEVCContexts
Andreas Rheinhardt
git at videolan.org
Tue Jul 26 00:59:00 EEST 2022
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Thu Jun 30 19:04:51 2022 +0200| [ad2b755d3f5c7870f7d2e14da5d1c5e7ca8f3786] | committer: Andreas Rheinhardt
avcodec/hevcdec: Don't allocate redundant HEVCContexts
The HEVC decoder has both HEVCContext and HEVCLocalContext
structures. The latter is supposed to be the structure
containing the per-slicethread state.
Yet up until now that is not how it is handled in practice:
Each HEVCLocalContext has a unique HEVCContext allocated for it
and each of these coincides except in exactly one field: The
corresponding HEVCLocalContext. This makes it possible to pass
the HEVCContext everywhere where logically a HEVCLocalContext
should be used. And up until recently, this is how it has been done.
Yet the preceding patches changed this, making it possible
to avoid allocating redundant HEVCContexts.
Reviewed-by: Michael Niedermayer <michael at niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ad2b755d3f5c7870f7d2e14da5d1c5e7ca8f3786
---
libavcodec/hevcdec.c | 43 +++++++++++++++++++------------------------
libavcodec/hevcdec.h | 2 --
2 files changed, 19 insertions(+), 26 deletions(-)
diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index d60cc6b786..b03cb15b7e 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -2549,13 +2549,12 @@ static int hls_decode_entry_wpp(AVCodecContext *avctxt, void *hevc_lclist,
{
HEVCLocalContext *lc = ((HEVCLocalContext**)hevc_lclist)[self_id];
const HEVCContext *const s = lc->parent;
- HEVCContext *s1 = avctxt->priv_data;
- int ctb_size = 1<< s1->ps.sps->log2_ctb_size;
+ int ctb_size = 1 << s->ps.sps->log2_ctb_size;
int more_data = 1;
int ctb_row = job;
- int ctb_addr_rs = s1->sh.slice_ctb_addr_rs + ctb_row * ((s1->ps.sps->width + ctb_size - 1) >> s1->ps.sps->log2_ctb_size);
- int ctb_addr_ts = s1->ps.pps->ctb_addr_rs_to_ts[ctb_addr_rs];
- int thread = ctb_row % s1->threads_number;
+ int ctb_addr_rs = s->sh.slice_ctb_addr_rs + ctb_row * ((s->ps.sps->width + ctb_size - 1) >> s->ps.sps->log2_ctb_size);
+ int ctb_addr_ts = s->ps.pps->ctb_addr_rs_to_ts[ctb_addr_rs];
+ int thread = ctb_row % s->threads_number;
int ret;
if(ctb_row) {
@@ -2573,7 +2572,10 @@ static int hls_decode_entry_wpp(AVCodecContext *avctxt, void *hevc_lclist,
ff_thread_await_progress2(s->avctx, ctb_row, thread, SHIFT_CTB_WPP);
- if (atomic_load(&s1->wpp_err)) {
+ /* atomic_load's prototype requires a pointer to non-const atomic variable
+ * (due to implementations via mutexes, where reads involve writes).
+ * Of course, casting const away here is nevertheless safe. */
+ if (atomic_load((atomic_int*)&s->wpp_err)) {
ff_thread_report_progress2(s->avctx, ctb_row , thread, SHIFT_CTB_WPP);
return 0;
}
@@ -2596,7 +2598,8 @@ static int hls_decode_entry_wpp(AVCodecContext *avctxt, void *hevc_lclist,
ff_hevc_hls_filters(lc, x_ctb, y_ctb, ctb_size);
if (!more_data && (x_ctb+ctb_size) < s->ps.sps->width && ctb_row != s->sh.num_entry_point_offsets) {
- atomic_store(&s1->wpp_err, 1);
+ /* Casting const away here is safe, because it is an atomic operation. */
+ atomic_store((atomic_int*)&s->wpp_err, 1);
ff_thread_report_progress2(s->avctx, ctb_row ,thread, SHIFT_CTB_WPP);
return 0;
}
@@ -2618,7 +2621,8 @@ static int hls_decode_entry_wpp(AVCodecContext *avctxt, void *hevc_lclist,
return 0;
error:
s->tab_slice_address[ctb_addr_rs] = -1;
- atomic_store(&s1->wpp_err, 1);
+ /* Casting const away here is safe, because it is an atomic operation. */
+ atomic_store((atomic_int*)&s->wpp_err, 1);
ff_thread_report_progress2(s->avctx, ctb_row ,thread, SHIFT_CTB_WPP);
return ret;
}
@@ -2648,18 +2652,15 @@ static int hls_slice_data_wpp(HEVCContext *s, const H2645NAL *nal)
ff_alloc_entries(s->avctx, s->sh.num_entry_point_offsets + 1);
for (i = 1; i < s->threads_number; i++) {
- if (s->sList[i] && s->HEVClcList[i])
+ if (s->HEVClcList[i])
continue;
- av_freep(&s->sList[i]);
- av_freep(&s->HEVClcList[i]);
- s->sList[i] = av_malloc(sizeof(HEVCContext));
s->HEVClcList[i] = av_mallocz(sizeof(HEVCLocalContext));
- if (!s->sList[i] || !s->HEVClcList[i]) {
+ if (!s->HEVClcList[i]) {
res = AVERROR(ENOMEM);
goto error;
}
s->HEVClcList[i]->logctx = s->avctx;
- s->HEVClcList[i]->parent = s->sList[i];
+ s->HEVClcList[i]->parent = s;
}
offset = (lc->gb.index >> 3);
@@ -2698,10 +2699,8 @@ static int hls_slice_data_wpp(HEVCContext *s, const H2645NAL *nal)
s->data = data;
for (i = 1; i < s->threads_number; i++) {
- memcpy(s->sList[i], s, sizeof(HEVCContext));
- s->sList[i]->HEVClc = s->HEVClcList[i];
- s->sList[i]->HEVClc->first_qp_group = 1;
- s->sList[i]->HEVClc->qp_y = s->sList[0]->HEVClc->qp_y;
+ s->HEVClcList[i]->first_qp_group = 1;
+ s->HEVClcList[i]->qp_y = s->HEVClc->qp_y;
}
atomic_store(&s->wpp_err, 0);
@@ -3610,15 +3609,13 @@ static av_cold int hevc_decode_free(AVCodecContext *avctx)
av_freep(&s->sh.offset);
av_freep(&s->sh.size);
- if (s->HEVClcList && s->sList) {
+ if (s->HEVClcList) {
for (i = 1; i < s->threads_number; i++) {
av_freep(&s->HEVClcList[i]);
- av_freep(&s->sList[i]);
}
}
av_freep(&s->HEVClc);
av_freep(&s->HEVClcList);
- av_freep(&s->sList);
ff_h2645_packet_uninit(&s->pkt);
@@ -3636,13 +3633,11 @@ static av_cold int hevc_init_context(AVCodecContext *avctx)
s->HEVClc = av_mallocz(sizeof(HEVCLocalContext));
s->HEVClcList = av_mallocz(sizeof(HEVCLocalContext*) * s->threads_number);
- s->sList = av_mallocz(sizeof(HEVCContext*) * s->threads_number);
- if (!s->HEVClc || !s->HEVClcList || !s->sList)
+ if (!s->HEVClc || !s->HEVClcList)
return AVERROR(ENOMEM);
s->HEVClc->parent = s;
s->HEVClc->logctx = avctx;
s->HEVClcList[0] = s->HEVClc;
- s->sList[0] = s;
s->cabac = av_malloc(sizeof(*s->cabac));
if (!s->cabac)
diff --git a/libavcodec/hevcdec.h b/libavcodec/hevcdec.h
index b33e8ae0f6..3367ee312a 100644
--- a/libavcodec/hevcdec.h
+++ b/libavcodec/hevcdec.h
@@ -476,8 +476,6 @@ typedef struct HEVCContext {
const AVClass *c; // needed by private avoptions
AVCodecContext *avctx;
- struct HEVCContext **sList;
-
HEVCLocalContext **HEVClcList;
HEVCLocalContext *HEVClc;
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