[FFmpeg-cvslog] h264: split reading the ref list modifications and actually building the ref list
Anton Khirnov
git at videolan.org
Wed Jun 29 17:36:13 CEST 2016
ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Fri Apr 15 16:10:21 2016 +0200| [ed9a20ebe4a89de119ea97bdccf688ece8c6648c] | committer: Anton Khirnov
h264: split reading the ref list modifications and actually building the ref list
This will allow postponing the reference list construction (and by
consequence some other functions, like frame_start) until the whole
slice header has been parsed.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ed9a20ebe4a89de119ea97bdccf688ece8c6648c
---
libavcodec/h264.h | 6 ++
libavcodec/h264_refs.c | 197 ++++++++++++++++++++++++++---------------------
libavcodec/h264_slice.c | 3 +
3 files changed, 118 insertions(+), 88 deletions(-)
diff --git a/libavcodec/h264.h b/libavcodec/h264.h
index 034507d..b4e5f3a 100644
--- a/libavcodec/h264.h
+++ b/libavcodec/h264.h
@@ -391,6 +391,11 @@ typedef struct H264SliceContext {
H264Ref ref_list[2][48]; /**< 0..15: frame refs, 16..47: mbaff field refs.
* Reordered version of default_ref_list
* according to picture reordering in slice header */
+ struct {
+ uint8_t op;
+ uint8_t val;
+ } ref_modifications[2][32];
+ int nb_ref_modifications[2];
const uint8_t *intra_pcm_ptr;
int16_t *dc_val_base;
@@ -657,6 +662,7 @@ int ff_h264_get_slice_type(const H264SliceContext *sl);
int ff_h264_alloc_tables(H264Context *h);
int ff_h264_decode_ref_pic_list_reordering(const H264Context *h, H264SliceContext *sl);
+int ff_h264_build_ref_list(const H264Context *h, H264SliceContext *sl);
void ff_h264_remove_all_refs(H264Context *h);
/**
diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
index b4dfbbc..ce3806c 100644
--- a/libavcodec/h264_refs.c
+++ b/libavcodec/h264_refs.c
@@ -252,7 +252,7 @@ static void h264_fill_mbaff_ref_list(H264SliceContext *sl)
}
}
-int ff_h264_decode_ref_pic_list_reordering(const H264Context *h, H264SliceContext *sl)
+int ff_h264_build_ref_list(const H264Context *h, H264SliceContext *sl)
{
int list, index, pic_structure;
@@ -262,102 +262,88 @@ int ff_h264_decode_ref_pic_list_reordering(const H264Context *h, H264SliceContex
h264_initialise_ref_list(h, sl);
for (list = 0; list < sl->list_count; list++) {
- if (get_bits1(&sl->gb)) { // ref_pic_list_modification_flag_l[01]
- int pred = h->curr_pic_num;
-
- for (index = 0; ; index++) {
- unsigned int modification_of_pic_nums_idc = get_ue_golomb_31(&sl->gb);
- unsigned int pic_id;
- int i;
- H264Picture *ref = NULL;
-
- if (modification_of_pic_nums_idc == 3)
- break;
-
- if (index >= sl->ref_count[list]) {
- av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n");
- return -1;
+ int pred = h->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;
+ unsigned int val = sl->ref_modifications[list][index].val;
+ unsigned int pic_id;
+ int i;
+ H264Picture *ref = NULL;
+
+ switch (modification_of_pic_nums_idc) {
+ case 0:
+ case 1: {
+ const unsigned int abs_diff_pic_num = val + 1;
+ int frame_num;
+
+ if (abs_diff_pic_num > h->max_pic_num) {
+ av_log(h->avctx, AV_LOG_ERROR,
+ "abs_diff_pic_num overflow\n");
+ return AVERROR_INVALIDDATA;
}
- switch (modification_of_pic_nums_idc) {
- case 0:
- case 1: {
- const unsigned int abs_diff_pic_num = get_ue_golomb(&sl->gb) + 1;
- int frame_num;
-
- if (abs_diff_pic_num > h->max_pic_num) {
- av_log(h->avctx, AV_LOG_ERROR,
- "abs_diff_pic_num overflow\n");
- return AVERROR_INVALIDDATA;
- }
-
- if (modification_of_pic_nums_idc == 0)
- pred -= abs_diff_pic_num;
- else
- pred += abs_diff_pic_num;
- pred &= h->max_pic_num - 1;
-
- frame_num = pic_num_extract(h, pred, &pic_structure);
-
- for (i = h->short_ref_count - 1; i >= 0; i--) {
- ref = h->short_ref[i];
- assert(ref->reference);
- assert(!ref->long_ref);
- if (ref->frame_num == frame_num &&
- (ref->reference & pic_structure))
- break;
- }
- if (i >= 0)
- ref->pic_id = pred;
- break;
+ if (modification_of_pic_nums_idc == 0)
+ pred -= abs_diff_pic_num;
+ else
+ pred += abs_diff_pic_num;
+ pred &= h->max_pic_num - 1;
+
+ frame_num = pic_num_extract(h, pred, &pic_structure);
+
+ for (i = h->short_ref_count - 1; i >= 0; i--) {
+ ref = h->short_ref[i];
+ assert(ref->reference);
+ assert(!ref->long_ref);
+ if (ref->frame_num == frame_num &&
+ (ref->reference & pic_structure))
+ break;
}
- case 2: {
- int long_idx;
- pic_id = get_ue_golomb(&sl->gb); // long_term_pic_idx
+ if (i >= 0)
+ ref->pic_id = pred;
+ break;
+ }
+ case 2: {
+ int long_idx;
+ pic_id = val; // long_term_pic_idx
- long_idx = pic_num_extract(h, pic_id, &pic_structure);
+ long_idx = pic_num_extract(h, pic_id, &pic_structure);
- if (long_idx > 31) {
- av_log(h->avctx, AV_LOG_ERROR,
- "long_term_pic_idx overflow\n");
- return AVERROR_INVALIDDATA;
- }
- ref = h->long_ref[long_idx];
- assert(!(ref && !ref->reference));
- if (ref && (ref->reference & pic_structure)) {
- ref->pic_id = pic_id;
- assert(ref->long_ref);
- i = 0;
- } else {
- i = -1;
- }
- break;
- }
- default:
+ if (long_idx > 31) {
av_log(h->avctx, AV_LOG_ERROR,
- "illegal modification_of_pic_nums_idc %u\n",
- modification_of_pic_nums_idc);
+ "long_term_pic_idx overflow\n");
return AVERROR_INVALIDDATA;
}
-
- if (i < 0) {
- av_log(h->avctx, AV_LOG_ERROR,
- "reference picture missing during reorder\n");
- memset(&sl->ref_list[list][index], 0, sizeof(sl->ref_list[0][0])); // FIXME
+ ref = h->long_ref[long_idx];
+ assert(!(ref && !ref->reference));
+ if (ref && (ref->reference & pic_structure)) {
+ ref->pic_id = pic_id;
+ assert(ref->long_ref);
+ i = 0;
} else {
- for (i = index; i + 1 < sl->ref_count[list]; i++) {
- if (sl->ref_list[list][i].parent &&
- ref->long_ref == sl->ref_list[list][i].parent->long_ref &&
- ref->pic_id == sl->ref_list[list][i].pic_id)
- break;
- }
- for (; i > index; i--) {
- sl->ref_list[list][i] = sl->ref_list[list][i - 1];
- }
- ref_from_h264pic(&sl->ref_list[list][index], ref);
- if (FIELD_PICTURE(h)) {
- pic_as_field(&sl->ref_list[list][index], pic_structure);
- }
+ i = -1;
+ }
+ break;
+ }
+ }
+
+ if (i < 0) {
+ av_log(h->avctx, AV_LOG_ERROR,
+ "reference picture missing during reorder\n");
+ memset(&sl->ref_list[list][index], 0, sizeof(sl->ref_list[0][0])); // FIXME
+ } else {
+ for (i = index; i + 1 < sl->ref_count[list]; i++) {
+ if (sl->ref_list[list][i].parent &&
+ ref->long_ref == sl->ref_list[list][i].parent->long_ref &&
+ ref->pic_id == sl->ref_list[list][i].pic_id)
+ break;
+ }
+ for (; i > index; i--) {
+ sl->ref_list[list][i] = sl->ref_list[list][i - 1];
+ }
+ ref_from_h264pic(&sl->ref_list[list][index], ref);
+ if (FIELD_PICTURE(h)) {
+ pic_as_field(&sl->ref_list[list][index], pic_structure);
}
}
}
@@ -380,6 +366,41 @@ int ff_h264_decode_ref_pic_list_reordering(const H264Context *h, H264SliceContex
return 0;
}
+int ff_h264_decode_ref_pic_list_reordering(const H264Context *h, H264SliceContext *sl)
+{
+ int list, index;
+
+ sl->nb_ref_modifications[0] = 0;
+ sl->nb_ref_modifications[1] = 0;
+
+ for (list = 0; list < sl->list_count; list++) {
+ if (!get_bits1(&sl->gb)) // ref_pic_list_modification_flag_l[01]
+ continue;
+
+ for (index = 0; ; index++) {
+ unsigned int op = get_ue_golomb_31(&sl->gb);
+
+ if (op == 3)
+ break;
+
+ if (index >= sl->ref_count[list]) {
+ av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n");
+ return AVERROR_INVALIDDATA;
+ } else if (op > 2) {
+ av_log(h->avctx, AV_LOG_ERROR,
+ "illegal modification_of_pic_nums_idc %u\n",
+ op);
+ return AVERROR_INVALIDDATA;
+ }
+ sl->ref_modifications[list][index].val = get_ue_golomb(&sl->gb);
+ sl->ref_modifications[list][index].op = op;
+ sl->nb_ref_modifications[list]++;
+ }
+ }
+
+ return 0;
+}
+
/**
* Mark a picture as no longer needed for reference. The refmask
* argument allows unreferencing of individual fields or the whole frame.
diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 031f8cc..b84514c 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -1347,6 +1347,9 @@ static int h264_slice_header_parse(H264Context *h, H264SliceContext *sl)
sl->ref_count[1] = sl->ref_count[0] = 0;
return ret;
}
+ ret = ff_h264_build_ref_list(h, sl);
+ if (ret < 0)
+ return ret;
}
if ((pps->weighted_pred && sl->slice_type_nos == AV_PICTURE_TYPE_P) ||
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