h264: use the main H264Context as the parent for all slice contexts

There is now no need to have per-slice copies of the H264Context.

3 files changed, 69 insertions, 111 deletions

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 8d213d765b..48ffeabbcd 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -655,7 +655,7 @@ av_cold int ff_h264_decode_init(AVCodecContext *avctx)
 
     h->thread_context[0] = h;
     for (i = 0; i < h->nb_slice_ctx; i++)
-        h->slice_ctx[i].h264 = h->thread_context[0];
+        h->slice_ctx[i].h264 = h;
 
     h->outputed_poc      = h->next_outputed_poc = INT_MIN;
     for (i = 0; i < MAX_DELAYED_PIC_COUNT; i++)
@@ -1422,7 +1422,6 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
                             int parse_extradata)
 {
     AVCodecContext *const avctx = h->avctx;
-    H264Context *hx; ///< thread context
     H264SliceContext *sl;
     int buf_index;
     unsigned context_count;
@@ -1468,10 +1467,9 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
                     continue;
             }
 
-            hx = h->thread_context[context_count];
             sl = &h->slice_ctx[context_count];
 
-            ptr = ff_h264_decode_nal(hx, sl, buf + buf_index, &dst_length,
+            ptr = ff_h264_decode_nal(h, sl, buf + buf_index, &dst_length,
                                      &consumed, next_avc - buf_index);
             if (!ptr || dst_length < 0) {
                 ret = -1;
@@ -1484,7 +1482,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
             if (h->avctx->debug & FF_DEBUG_STARTCODE)
                 av_log(h->avctx, AV_LOG_DEBUG,
                        "NAL %d at %d/%d length %d\n",
-                       hx->nal_unit_type, buf_index, buf_size, dst_length);
+                       h->nal_unit_type, buf_index, buf_size, dst_length);
 
             if (h->is_avc && (nalsize != consumed) && nalsize)
                 av_log(h->avctx, AV_LOG_DEBUG,
@@ -1505,17 +1503,17 @@ again:
              * with frame-mt */
             if (parse_extradata && HAVE_THREADS &&
                 (h->avctx->active_thread_type & FF_THREAD_FRAME) &&
-                (hx->nal_unit_type != NAL_PPS &&
-                 hx->nal_unit_type != NAL_SPS)) {
-                if (hx->nal_unit_type < NAL_AUD ||
-                    hx->nal_unit_type > NAL_AUXILIARY_SLICE)
+                (h->nal_unit_type != NAL_PPS &&
+                 h->nal_unit_type != NAL_SPS)) {
+                if (h->nal_unit_type < NAL_AUD ||
+                    h->nal_unit_type > NAL_AUXILIARY_SLICE)
                     av_log(avctx, AV_LOG_INFO,
                            "Ignoring NAL unit %d during extradata parsing\n",
-                           hx->nal_unit_type);
-                hx->nal_unit_type = NAL_FF_IGNORE;
+                           h->nal_unit_type);
+                h->nal_unit_type = NAL_FF_IGNORE;
             }
             err = 0;
-            switch (hx->nal_unit_type) {
+            switch (h->nal_unit_type) {
             case NAL_IDR_SLICE:
                 if (h->nal_unit_type != NAL_IDR_SLICE) {
                     av_log(h->avctx, AV_LOG_ERROR,
@@ -1527,7 +1525,7 @@ again:
             case NAL_SLICE:
                 init_get_bits(&sl->gb, ptr, bit_length);
 
-                if ((err = ff_h264_decode_slice_header(hx, sl, h)))
+                if ((err = ff_h264_decode_slice_header(h, sl)))
                     break;
 
                 if (h->sei_recovery_frame_cnt >= 0 && h->recovery_frame < 0) {
@@ -1536,17 +1534,17 @@ again:
                 }
 
                 h->cur_pic_ptr->f.key_frame |=
-                    (hx->nal_unit_type == NAL_IDR_SLICE) ||
+                    (h->nal_unit_type == NAL_IDR_SLICE) ||
                     (h->sei_recovery_frame_cnt >= 0);
 
-                if (hx->nal_unit_type == NAL_IDR_SLICE ||
+                if (h->nal_unit_type == NAL_IDR_SLICE ||
                     h->recovery_frame == h->frame_num) {
                     h->recovery_frame         = -1;
                     h->cur_pic_ptr->recovered = 1;
                 }
                 // If we have an IDR, all frames after it in decoded order are
                 // "recovered".
-                if (hx->nal_unit_type == NAL_IDR_SLICE)
+                if (h->nal_unit_type == NAL_IDR_SLICE)
                     h->frame_recovered |= FRAME_RECOVERED_IDR;
                 h->cur_pic_ptr->recovered |= !!(h->frame_recovered & FRAME_RECOVERED_IDR);
 
@@ -1561,7 +1559,7 @@ again:
 
                 if (sl->redundant_pic_count == 0 &&
                     (avctx->skip_frame < AVDISCARD_NONREF ||
-                     hx->nal_ref_idc) &&
+                     h->nal_ref_idc) &&
                     (avctx->skip_frame < AVDISCARD_BIDIR  ||
                      sl->slice_type_nos != AV_PICTURE_TYPE_B) &&
                     (avctx->skip_frame < AVDISCARD_NONKEY ||
@@ -1623,7 +1621,7 @@ again:
                 break;
             default:
                 av_log(avctx, AV_LOG_DEBUG, "Unknown NAL code: %d (%d bits)\n",
-                       hx->nal_unit_type, bit_length);
+                       h->nal_unit_type, bit_length);
             }
 
             if (context_count == h->max_contexts) {
@@ -1637,13 +1635,9 @@ again:
                 av_log(h->avctx, AV_LOG_ERROR, "decode_slice_header error\n");
                 sl->ref_count[0] = sl->ref_count[1] = sl->list_count = 0;
             } else if (err == 1) {
-                /* Slice could not be decoded in parallel mode, copy down
-                 * NAL unit stuff to context 0 and restart. Note that
-                 * rbsp_buffer is not transferred, but since we no longer
+                /* Slice could not be decoded in parallel mode, restart. Note
+                 * that rbsp_buffer is not transferred, but since we no longer
                  * run in parallel mode this should not be an issue. */
-                h->nal_unit_type = hx->nal_unit_type;
-                h->nal_ref_idc   = hx->nal_ref_idc;
-                hx               = h;
                 sl               = &h->slice_ctx[0];
                 goto again;
             }
diff --git a/libavcodec/h264.h b/libavcodec/h264.h
index 594c65db8f..a24c7c7253 100644
--- a/libavcodec/h264.h
+++ b/libavcodec/h264.h
@@ -1070,7 +1070,7 @@ int ff_init_poc(H264Context *h, int pic_field_poc[2], int *pic_poc);
 int ff_pred_weight_table(H264Context *h, H264SliceContext *sl);
 int ff_set_ref_count(H264Context *h, H264SliceContext *sl);
 
-int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Context *h0);
+int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl);
 int ff_h264_execute_decode_slices(H264Context *h, unsigned context_count);
 int ff_h264_update_thread_context(AVCodecContext *dst,
                                   const AVCodecContext *src);
diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index ba5456eb45..40ed93cad9 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -904,34 +904,6 @@ static void init_scan_tables(H264Context *h)
     }
 }
 
-/**
- * Replicate H264 "master" context to thread contexts.
- */
-static int clone_slice(H264Context *dst, H264Context *src)
-{
-    memcpy(dst->block_offset, src->block_offset, sizeof(dst->block_offset));
-    dst->cur_pic_ptr = src->cur_pic_ptr;
-    dst->cur_pic     = src->cur_pic;
-    dst->linesize    = src->linesize;
-    dst->uvlinesize  = src->uvlinesize;
-    dst->first_field = src->first_field;
-
-    dst->prev_poc_msb          = src->prev_poc_msb;
-    dst->prev_poc_lsb          = src->prev_poc_lsb;
-    dst->prev_frame_num_offset = src->prev_frame_num_offset;
-    dst->prev_frame_num        = src->prev_frame_num;
-    dst->short_ref_count       = src->short_ref_count;
-
-    memcpy(dst->short_ref,        src->short_ref,        sizeof(dst->short_ref));
-    memcpy(dst->long_ref,         src->long_ref,         sizeof(dst->long_ref));
-    memcpy(dst->default_ref_list, src->default_ref_list, sizeof(dst->default_ref_list));
-
-    memcpy(dst->dequant4_coeff,   src->dequant4_coeff,   sizeof(src->dequant4_coeff));
-    memcpy(dst->dequant8_coeff,   src->dequant8_coeff,   sizeof(src->dequant8_coeff));
-
-    return 0;
-}
-
 static enum AVPixelFormat get_pixel_format(H264Context *h)
 {
 #define HWACCEL_MAX (CONFIG_H264_DXVA2_HWACCEL + \
@@ -1154,12 +1126,10 @@ static int h264_slice_header_init(H264Context *h, int reinit)
  * This will (re)intialize the decoder and call h264_frame_start() as needed.
  *
  * @param h h264context
- * @param h0 h264 master context (differs from 'h' when doing sliced based
- *           parallel decoding)
  *
  * @return 0 if okay, <0 if an error occurred, 1 if decoding must not be multithreaded
  */
-int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Context *h0)
+int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl)
 {
     unsigned int first_mb_in_slice;
     unsigned int pps_id;
@@ -1176,12 +1146,12 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
     first_mb_in_slice = get_ue_golomb(&sl->gb);
 
     if (first_mb_in_slice == 0) { // FIXME better field boundary detection
-        if (h0->current_slice && h->cur_pic_ptr && FIELD_PICTURE(h)) {
+        if (h->current_slice && h->cur_pic_ptr && FIELD_PICTURE(h)) {
             ff_h264_field_end(h, sl, 1);
         }
 
-        h0->current_slice = 0;
-        if (!h0->first_field) {
+        h->current_slice = 0;
+        if (!h->first_field) {
             if (h->cur_pic_ptr && !h->droppable) {
                 ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                           h->picture_structure == PICT_BOTTOM_FIELD);
@@ -1205,7 +1175,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
 
     slice_type = golomb_to_pict_type[slice_type];
     if (slice_type == AV_PICTURE_TYPE_I ||
-        (h0->current_slice != 0 && slice_type == h0->last_slice_type)) {
+        (h->current_slice != 0 && slice_type == h->last_slice_type)) {
         default_ref_list_done = 1;
     }
     sl->slice_type     = slice_type;
@@ -1225,15 +1195,15 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
         av_log(h->avctx, AV_LOG_ERROR, "pps_id %u out of range\n", pps_id);
         return AVERROR_INVALIDDATA;
     }
-    if (!h0->pps_buffers[pps_id]) {
+    if (!h->pps_buffers[pps_id]) {
         av_log(h->avctx, AV_LOG_ERROR,
                "non-existing PPS %u referenced\n",
                pps_id);
         return AVERROR_INVALIDDATA;
     }
-    h->pps = *h0->pps_buffers[pps_id];
+    h->pps = *h->pps_buffers[pps_id];
 
-    if (!h0->sps_buffers[h->pps.sps_id]) {
+    if (!h->sps_buffers[h->pps.sps_id]) {
         av_log(h->avctx, AV_LOG_ERROR,
                "non-existing SPS %u referenced\n",
                h->pps.sps_id);
@@ -1241,10 +1211,10 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
     }
 
     if (h->pps.sps_id != h->sps.sps_id ||
-        h0->sps_buffers[h->pps.sps_id]->new) {
-        h0->sps_buffers[h->pps.sps_id]->new = 0;
+        h->sps_buffers[h->pps.sps_id]->new) {
+        h->sps_buffers[h->pps.sps_id]->new = 0;
 
-        h->sps = *h0->sps_buffers[h->pps.sps_id];
+        h->sps = *h->sps_buffers[h->pps.sps_id];
 
         if (h->bit_depth_luma    != h->sps.bit_depth_luma ||
             h->chroma_format_idc != h->sps.chroma_format_idc) {
@@ -1293,13 +1263,13 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
     }
 
     if (h->context_initialized && needs_reinit) {
-        if (h != h0) {
+        if (sl != h->slice_ctx) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "changing width %d -> %d / height %d -> %d on "
                    "slice %d\n",
                    h->width, h->avctx->coded_width,
                    h->height, h->avctx->coded_height,
-                   h0->current_slice + 1);
+                   h->current_slice + 1);
             return AVERROR_INVALIDDATA;
         }
 
@@ -1319,7 +1289,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
         }
     }
     if (!h->context_initialized) {
-        if (h != h0) {
+        if (sl != h->slice_ctx) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "Cannot (re-)initialize context during parallel decoding.\n");
             return AVERROR_PATCHWELCOME;
@@ -1336,7 +1306,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
         }
     }
 
-    if (h == h0 && h->dequant_coeff_pps != pps_id) {
+    if (sl == h->slice_ctx && h->dequant_coeff_pps != pps_id) {
         h->dequant_coeff_pps = pps_id;
         h264_init_dequant_tables(h);
     }
@@ -1345,8 +1315,8 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
 
     sl->mb_mbaff       = 0;
     h->mb_aff_frame    = 0;
-    last_pic_structure = h0->picture_structure;
-    last_pic_droppable = h0->droppable;
+    last_pic_structure = h->picture_structure;
+    last_pic_droppable = h->droppable;
     h->droppable       = h->nal_ref_idc == 0;
     if (h->sps.frame_mbs_only_flag) {
         h->picture_structure = PICT_FRAME;
@@ -1362,7 +1332,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
     }
     sl->mb_field_decoding_flag = h->picture_structure != PICT_FRAME;
 
-    if (h0->current_slice != 0) {
+    if (h->current_slice != 0) {
         if (last_pic_structure != h->picture_structure ||
             last_pic_droppable != h->droppable) {
             av_log(h->avctx, AV_LOG_ERROR,
@@ -1371,10 +1341,10 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
             h->picture_structure = last_pic_structure;
             h->droppable         = last_pic_droppable;
             return AVERROR_INVALIDDATA;
-        } else if (!h0->cur_pic_ptr) {
+        } else if (!h->cur_pic_ptr) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "unset cur_pic_ptr on slice %d\n",
-                   h0->current_slice + 1);
+                   h->current_slice + 1);
             return AVERROR_INVALIDDATA;
         }
     } else {
@@ -1401,27 +1371,27 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
          * decode frames as "finished".
          * We have to do that before the "dummy" in-between frame allocation,
          * since that can modify s->current_picture_ptr. */
-        if (h0->first_field) {
-            assert(h0->cur_pic_ptr);
-            assert(h0->cur_pic_ptr->f.buf[0]);
-            assert(h0->cur_pic_ptr->reference != DELAYED_PIC_REF);
+        if (h->first_field) {
+            assert(h->cur_pic_ptr);
+            assert(h->cur_pic_ptr->f.buf[0]);
+            assert(h->cur_pic_ptr->reference != DELAYED_PIC_REF);
 
             /* figure out if we have a complementary field pair */
             if (!FIELD_PICTURE(h) || h->picture_structure == last_pic_structure) {
                 /* Previous field is unmatched. Don't display it, but let it
                  * remain for reference if marked as such. */
                 if (!last_pic_droppable && last_pic_structure != PICT_FRAME) {
-                    ff_thread_report_progress(&h0->cur_pic_ptr->tf, INT_MAX,
+                    ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                               last_pic_structure == PICT_TOP_FIELD);
                 }
             } else {
-                if (h0->cur_pic_ptr->frame_num != h->frame_num) {
+                if (h->cur_pic_ptr->frame_num != h->frame_num) {
                     /* This and previous field were reference, but had
                      * different frame_nums. Consider this field first in
                      * pair. Throw away previous field except for reference
                      * purposes. */
                     if (!last_pic_droppable && last_pic_structure != PICT_FRAME) {
-                        ff_thread_report_progress(&h0->cur_pic_ptr->tf, INT_MAX,
+                        ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                                   last_pic_structure == PICT_TOP_FIELD);
                     }
                 } else {
@@ -1454,7 +1424,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
                    h->frame_num, h->prev_frame_num);
             ret = h264_frame_start(h);
             if (ret < 0) {
-                h0->first_field = 0;
+                h->first_field = 0;
                 return ret;
             }
 
@@ -1494,45 +1464,43 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
         /* See if we have a decoded first field looking for a pair...
          * We're using that to see whether to continue decoding in that
          * frame, or to allocate a new one. */
-        if (h0->first_field) {
-            assert(h0->cur_pic_ptr);
-            assert(h0->cur_pic_ptr->f.buf[0]);
-            assert(h0->cur_pic_ptr->reference != DELAYED_PIC_REF);
+        if (h->first_field) {
+            assert(h->cur_pic_ptr);
+            assert(h->cur_pic_ptr->f.buf[0]);
+            assert(h->cur_pic_ptr->reference != DELAYED_PIC_REF);
 
             /* figure out if we have a complementary field pair */
             if (!FIELD_PICTURE(h) || h->picture_structure == last_pic_structure) {
                 /* Previous field is unmatched. Don't display it, but let it
                  * remain for reference if marked as such. */
-                h0->cur_pic_ptr = NULL;
-                h0->first_field = FIELD_PICTURE(h);
+                h->cur_pic_ptr = NULL;
+                h->first_field = FIELD_PICTURE(h);
             } else {
-                if (h0->cur_pic_ptr->frame_num != h->frame_num) {
+                if (h->cur_pic_ptr->frame_num != h->frame_num) {
                     /* This and the previous field had different frame_nums.
                      * Consider this field first in pair. Throw away previous
                      * one except for reference purposes. */
-                    h0->first_field = 1;
-                    h0->cur_pic_ptr = NULL;
+                    h->first_field = 1;
+                    h->cur_pic_ptr = NULL;
                 } else {
                     /* Second field in complementary pair */
-                    h0->first_field = 0;
+                    h->first_field = 0;
                 }
             }
         } else {
             /* Frame or first field in a potentially complementary pair */
-            h0->first_field = FIELD_PICTURE(h);
+            h->first_field = FIELD_PICTURE(h);
         }
 
-        if (!FIELD_PICTURE(h) || h0->first_field) {
+        if (!FIELD_PICTURE(h) || h->first_field) {
             if (h264_frame_start(h) < 0) {
-                h0->first_field = 0;
+                h->first_field = 0;
                 return AVERROR_INVALIDDATA;
             }
         } else {
             release_unused_pictures(h, 0);
         }
     }
-    if (h != h0 && (ret = clone_slice(h, h0)) < 0)
-        return ret;
 
     h->cur_pic_ptr->frame_num = h->frame_num; // FIXME frame_num cleanup
 
@@ -1617,9 +1585,9 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
     // further down the line. This may break decoding if the first slice is
     // corrupt, thus we only do this if frame-mt is enabled.
     if (h->nal_ref_idc) {
-        ret = ff_h264_decode_ref_pic_marking(h0, &sl->gb,
+        ret = ff_h264_decode_ref_pic_marking(h, &sl->gb,
                                              !(h->avctx->active_thread_type & FF_THREAD_FRAME) ||
-                                             h0->current_slice == 0);
+                                             h->current_slice == 0);
         if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))
             return AVERROR_INVALIDDATA;
     }
@@ -1700,19 +1668,19 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
          h->nal_ref_idc == 0))
         sl->deblocking_filter = 0;
 
-    if (sl->deblocking_filter == 1 && h0->max_contexts > 1) {
+    if (sl->deblocking_filter == 1 && h->max_contexts > 1) {
         if (h->avctx->flags2 & CODEC_FLAG2_FAST) {
             /* Cheat slightly for speed:
              * Do not bother to deblock across slices. */
             sl->deblocking_filter = 2;
         } else {
-            h0->max_contexts = 1;
-            if (!h0->single_decode_warning) {
+            h->max_contexts = 1;
+            if (!h->single_decode_warning) {
                 av_log(h->avctx, AV_LOG_INFO,
                        "Cannot parallelize deblocking type 1, decoding such frames in sequential order\n");
-                h0->single_decode_warning = 1;
+                h->single_decode_warning = 1;
             }
-            if (h != h0) {
+            if (sl != h->slice_ctx) {
                 av_log(h->avctx, AV_LOG_ERROR,
                        "Deblocking switched inside frame.\n");
                 return 1;
@@ -1726,8 +1694,8 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
                           h->pps.chroma_qp_index_offset[1]) +
                    6 * (h->sps.bit_depth_luma - 8);
 
-    h0->last_slice_type = slice_type;
-    sl->slice_num       = ++h0->current_slice;
+    h->last_slice_type = slice_type;
+    sl->slice_num       = ++h->current_slice;
     if (sl->slice_num >= MAX_SLICES) {
         av_log(h->avctx, AV_LOG_ERROR,
                "Too many slices, increase MAX_SLICES and recompile\n");
@@ -2336,7 +2304,6 @@ static int decode_slice(struct AVCodecContext *avctx, void *arg)
 int ff_h264_execute_decode_slices(H264Context *h, unsigned context_count)
 {
     AVCodecContext *const avctx = h->avctx;
-    H264Context *hx;
     H264SliceContext *sl;
     int i;
 
@@ -2356,11 +2323,8 @@ int ff_h264_execute_decode_slices(H264Context *h, unsigned context_count)
                        NULL, context_count, sizeof(h->slice_ctx[0]));
 
         /* pull back stuff from slices to master context */
-        hx                   = h->thread_context[context_count - 1];
         sl                   = &h->slice_ctx[context_count - 1];
         h->mb_y              = sl->mb_y;
-        h->droppable         = hx->droppable;
-        h->picture_structure = hx->picture_structure;
         for (i = 1; i < context_count; i++)
             h->slice_ctx[0].er.error_count += h->slice_ctx[i].er.error_count;
     }