h264: store {curr,max}_pic_num in the per-slice context

While the value of those variables will be constant for the whole frame,
they are only used in two functions called from slice header decoding.
Moving them to the per-slice context allows us to make the H264Context
passed to slice_header_parse() constant.

diff --git a/libavcodec/h264.h b/libavcodec/h264.h
index 4a109e119c2c5a23377791285838855e3b8f6047..cc7dd7ffea521184f51db308180670d53b781d2c 100644 (file)
--- a/libavcodec/h264.h
+++ b/libavcodec/h264.h
@@ -451,6 +451,8 @@ typedef struct H264SliceContext {
     int poc_lsb;
     int delta_poc_bottom;
     int delta_poc[2];
+    int curr_pic_num;
+    int max_pic_num;
 } H264SliceContext;
 
 /**
@@ -565,16 +567,6 @@ typedef struct H264Context {
 
     H264POCContext poc;
 
-    /**
-     * frame_num for frames or 2 * frame_num + 1 for field pics.
-     */
-    int curr_pic_num;
-
-    /**
-     * max_frame_num or 2 * max_frame_num for field pics.
-     */
-    int max_pic_num;
-
     H264Picture *short_ref[32];
     H264Picture *long_ref[32];
     H264Picture *delayed_pic[MAX_DELAYED_PIC_COUNT + 2]; // FIXME size?

diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
index 2e43a8f4e543c2c8fe2336685e17155839c54062..f7b7211a5c2261070d4ab135d72b9e687d9de3b9 100644 (file)
--- a/libavcodec/h264_refs.c
+++ b/libavcodec/h264_refs.c
@@ -262,7 +262,7 @@ int ff_h264_build_ref_list(const H264Context *h, H264SliceContext *sl)
     h264_initialise_ref_list(h, sl);
 
     for (list = 0; list < sl->list_count; list++) {
-        int pred = h->curr_pic_num;
+        int pred = sl->curr_pic_num;
 
         for (index = 0; index < sl->nb_ref_modifications[list]; index++) {
             unsigned int modification_of_pic_nums_idc = sl->ref_modifications[list][index].op;
@@ -277,7 +277,7 @@ int ff_h264_build_ref_list(const H264Context *h, H264SliceContext *sl)
                 const unsigned int abs_diff_pic_num = val + 1;
                 int frame_num;
 
-                if (abs_diff_pic_num > h->max_pic_num) {
+                if (abs_diff_pic_num > sl->max_pic_num) {
                     av_log(h->avctx, AV_LOG_ERROR,
                            "abs_diff_pic_num overflow\n");
                     return AVERROR_INVALIDDATA;
@@ -287,7 +287,7 @@ int ff_h264_build_ref_list(const H264Context *h, H264SliceContext *sl)
                     pred -= abs_diff_pic_num;
                 else
                     pred += abs_diff_pic_num;
-                pred &= h->max_pic_num - 1;
+                pred &= sl->max_pic_num - 1;
 
                 frame_num = pic_num_extract(h, pred, &pic_structure);
 
@@ -751,8 +751,8 @@ int ff_h264_decode_ref_pic_marking(const H264Context *h, H264SliceContext *sl,
                 mmco[i].opcode = opcode;
                 if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG) {
                     mmco[i].short_pic_num =
-                        (h->curr_pic_num - get_ue_golomb(gb) - 1) &
-                            (h->max_pic_num - 1);
+                        (sl->curr_pic_num - get_ue_golomb(gb) - 1) &
+                            (sl->max_pic_num - 1);
 #if 0
                     if (mmco[i].short_pic_num >= h->short_ref_count ||
                         !h->short_ref[mmco[i].short_pic_num]) {

diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index be44e66b3ea2868908f89ec145a6710bc0cc9a36..d9268840bffc51f2d0b33f0229319815d2100415 100644 (file)
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -405,9 +405,6 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
 
     memcpy(&h->poc,        &h1->poc,        sizeof(h->poc));
 
-    h->curr_pic_num      = h1->curr_pic_num;
-    h->max_pic_num       = h1->max_pic_num;
-
     memcpy(h->short_ref,   h1->short_ref,   sizeof(h->short_ref));
     memcpy(h->long_ref,    h1->long_ref,    sizeof(h->long_ref));
     memcpy(h->delayed_pic, h1->delayed_pic, sizeof(h->delayed_pic));
@@ -1173,7 +1170,7 @@ static int h264_field_start(H264Context *h, const H264SliceContext *sl,
     return 0;
 }
 
-static int h264_slice_header_parse(H264Context *h, H264SliceContext *sl,
+static int h264_slice_header_parse(const H264Context *h, H264SliceContext *sl,
                                    const H2645NAL *nal)
 {
     const SPS *sps;
@@ -1248,11 +1245,11 @@ static int h264_slice_header_parse(H264Context *h, H264SliceContext *sl,
     sl->mb_field_decoding_flag = picture_structure != PICT_FRAME;
 
     if (picture_structure == PICT_FRAME) {
-        h->curr_pic_num = sl->frame_num;
-        h->max_pic_num  = 1 << sps->log2_max_frame_num;
+        sl->curr_pic_num = sl->frame_num;
+        sl->max_pic_num  = 1 << sps->log2_max_frame_num;
     } else {
-        h->curr_pic_num = 2 * sl->frame_num + 1;
-        h->max_pic_num  = 1 << (sps->log2_max_frame_num + 1);
+        sl->curr_pic_num = 2 * sl->frame_num + 1;
+        sl->max_pic_num  = 1 << (sps->log2_max_frame_num + 1);
     }
 
     if (nal->type == NAL_IDR_SLICE)