Merge commit 'e0652795292223f8bc8e5bac019c1fca7323d23c'

* commit 'e0652795292223f8bc8e5bac019c1fca7323d23c':
  h264: remove an artificial restriction on the number of slice threads

Tested with multiple runs of fate-h264 THREADS=50 THREAD_TYPE=slice

Merged-by: Clément Bœsch <clement@stupeflix.com>

libavcodec/h264.c

@@ -312,7 +312,6 @@ static int h264_init_context(AVCodecContext *avctx, H264Context *h)
     h->cur_chroma_format_idc = -1;
 
     h->picture_structure     = PICT_FRAME;
-    h->slice_context_count   = 1;
     h->workaround_bugs       = avctx->workaround_bugs;
     h->flags                 = avctx->flags;
     h->poc.prev_poc_msb      = 1 << 16;
@@ -330,7 +329,7 @@ static int h264_init_context(AVCodecContext *avctx, H264Context *h)
 
     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
 
-    h->nb_slice_ctx = (avctx->active_thread_type & FF_THREAD_SLICE) ?  H264_MAX_THREADS : 1;
+    h->nb_slice_ctx = (avctx->active_thread_type & FF_THREAD_SLICE) ? avctx->thread_count : 1;
     h->slice_ctx = av_mallocz_array(h->nb_slice_ctx, sizeof(*h->slice_ctx));
     if (!h->slice_ctx) {
         h->nb_slice_ctx = 0;
@@ -883,9 +882,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size)
 
     h->nal_unit_type= 0;
 
-    if(!h->slice_context_count)
-         h->slice_context_count= 1;
-    h->max_contexts = h->slice_context_count;
+    h->max_contexts = h->nb_slice_ctx;
     if (!(avctx->flags2 & AV_CODEC_FLAG2_CHUNKS)) {
         h->current_slice = 0;
         if (!h->first_field)

libavcodec/h264.h

@@ -49,7 +49,6 @@
 #include "videodsp.h"
 
 #define H264_MAX_PICTURE_COUNT 36
-#define H264_MAX_THREADS       32
 
 #define MAX_SPS_COUNT          32
 #define MAX_PPS_COUNT         256
@@ -623,8 +622,6 @@ typedef struct H264Context {
      */
     int max_contexts;
 
-    int slice_context_count;
-
     /**
      *  1 if the single thread fallback warning has already been
      *  displayed, 0 otherwise.

libavcodec/h264_slice.c

@@ -917,9 +917,6 @@ static int init_dimensions(H264Context *h)
 static int h264_slice_header_init(H264Context *h)
 {
     const SPS *sps = h->ps.sps;
-    int nb_slices = (HAVE_THREADS &&
-                     h->avctx->active_thread_type & FF_THREAD_SLICE) ?
-                    h->avctx->thread_count : 1;
     int i, ret;
 
     ff_set_sar(h->avctx, sps->sar);
@@ -981,19 +978,6 @@ static int h264_slice_header_init(H264Context *h)
                       sps->chroma_format_idc);
     ff_videodsp_init(&h->vdsp, sps->bit_depth_luma);
 
-    if (nb_slices > H264_MAX_THREADS || (nb_slices > h->mb_height && h->mb_height)) {
-        int max_slices;
-        if (h->mb_height)
-            max_slices = FFMIN(H264_MAX_THREADS, h->mb_height);
-        else
-            max_slices = H264_MAX_THREADS;
-        av_log(h->avctx, AV_LOG_WARNING, "too many threads/slices %d,"
-               " reducing to %d\n", nb_slices, max_slices);
-        nb_slices = max_slices;
-    }
-    h->slice_context_count = nb_slices;
-    h->max_contexts = FFMIN(h->max_contexts, nb_slices);
-
     if (!HAVE_THREADS || !(h->avctx->active_thread_type & FF_THREAD_SLICE)) {
         ret = ff_h264_slice_context_init(h, &h->slice_ctx[0]);
         if (ret < 0) {
@@ -1001,7 +985,7 @@ static int h264_slice_header_init(H264Context *h)
             goto fail;
         }
     } else {
-        for (i = 0; i < h->slice_context_count; i++) {
+        for (i = 0; i < h->nb_slice_ctx; i++) {
             H264SliceContext *sl = &h->slice_ctx[i];
 
             sl->h264               = h;