h264: move the scratch buffers into the per-slice context

Also change the method for allocating them. Instead of two possible
alloc calls from different places, just ensure they are allocated at the
start of each slice. This should be simpler and less bug-prone than the
previous method.

1 files changed, 13 insertions, 30 deletions

diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index e8168713a8..30dd5c350d 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -157,21 +157,20 @@ static void release_unused_pictures(H264Context *h, int remove_current)
     }
 }
 
-static int alloc_scratch_buffers(H264Context *h, int linesize)
+static int alloc_scratch_buffers(H264SliceContext *sl, int linesize)
 {
     int alloc_size = FFALIGN(FFABS(linesize) + 32, 32);
 
-    if (h->bipred_scratchpad)
-        return 0;
-
-    h->bipred_scratchpad = av_malloc(16 * 6 * alloc_size);
+    av_fast_malloc(&sl->bipred_scratchpad, &sl->bipred_scratchpad_allocated, 16 * 6 * alloc_size);
     // edge emu needs blocksize + filter length - 1
     // (= 21x21 for  h264)
-    h->edge_emu_buffer = av_mallocz(alloc_size * 2 * 21);
+    av_fast_malloc(&sl->edge_emu_buffer, &sl->edge_emu_buffer_allocated, alloc_size * 2 * 21);
 
-    if (!h->bipred_scratchpad || !h->edge_emu_buffer) {
-        av_freep(&h->bipred_scratchpad);
-        av_freep(&h->edge_emu_buffer);
+    if (!sl->bipred_scratchpad || !sl->edge_emu_buffer) {
+        av_freep(&sl->bipred_scratchpad);
+        av_freep(&sl->edge_emu_buffer);
+        sl->bipred_scratchpad_allocated = 0;
+        sl->edge_emu_buffer_allocated   = 0;
         return AVERROR(ENOMEM);
     }
 
@@ -381,8 +380,6 @@ static void clone_tables(H264Context *dst, H264SliceContext *sl,
     dst->DPB                    = src->DPB;
     dst->cur_pic_ptr            = src->cur_pic_ptr;
     dst->cur_pic                = src->cur_pic;
-    dst->bipred_scratchpad      = NULL;
-    dst->edge_emu_buffer        = NULL;
     ff_h264_pred_init(&dst->hpc, src->avctx->codec_id, src->sps.bit_depth_luma,
                       src->sps.chroma_format_idc);
 }
@@ -460,8 +457,6 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
          * the current value */
         h->avctx->bits_per_raw_sample = h->sps.bit_depth_luma;
 
-        av_freep(&h->bipred_scratchpad);
-
         h->width     = h1->width;
         h->height    = h1->height;
         h->mb_height = h1->mb_height;
@@ -530,8 +525,6 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
 
         h->rbsp_buffer      = NULL;
         h->rbsp_buffer_size = 0;
-        h->bipred_scratchpad = NULL;
-        h->edge_emu_buffer   = NULL;
 
         h->thread_context[0] = h;
 
@@ -567,12 +560,6 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
     h->low_delay       = h1->low_delay;
     h->droppable       = h1->droppable;
 
-    /* frame_start may not be called for the next thread (if it's decoding
-     * a bottom field) so this has to be allocated here */
-    err = alloc_scratch_buffers(h, h1->linesize);
-    if (err < 0)
-        return err;
-
     // extradata/NAL handling
     h->is_avc = h1->is_avc;
 
@@ -688,15 +675,6 @@ static int h264_frame_start(H264Context *h)
         h->block_offset[48 + 32 + i] = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 8 * h->uvlinesize * ((scan8[i] - scan8[0]) >> 3);
     }
 
-    /* can't be in alloc_tables because linesize isn't known there.
-     * FIXME: redo bipred weight to not require extra buffer? */
-    for (i = 0; i < h->slice_context_count; i++)
-        if (h->thread_context[i]) {
-            ret = alloc_scratch_buffers(h->thread_context[i], h->linesize);
-            if (ret < 0)
-                return ret;
-        }
-
     /* Some macroblocks can be accessed before they're available in case
      * of lost slices, MBAFF or threading. */
     memset(h->slice_table, -1,
@@ -2181,6 +2159,11 @@ static int decode_slice(struct AVCodecContext *avctx, void *arg)
     H264SliceContext *sl = arg;
     H264Context       *h = sl->h264;
     int lf_x_start = sl->mb_x;
+    int ret;
+
+    ret = alloc_scratch_buffers(sl, h->linesize);
+    if (ret < 0)
+        return ret;
 
     sl->mb_skip_run = -1;