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h264: fix deadlocks on incomplete reference frame decoding.

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If decoding a second complementary field, and the first was
decoded in our thread, mark decoding of that field as complete.
If decoding fails, mark the decoded field/frame as complete.
Do not allow switching between field modes or field/frame mode
between slices within the same field/frame. Ensure that two
subsequent fields cover top/bottom (rather than top/frame,
bottom/frame or such nonsense situations).

Fixes various deadlocks when decoding samples with errors in
reference frames.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit 1e26a48fa2)

Fixes Bug 118

Conflicts:
	libavcodec/h264.c

Signed-off-by: Anton Khirnov <anton@khirnov.net>
This commit is contained in:
Ronald S. Bultje
2012-03-16 15:24:08 -07:00
committed by Anton Khirnov
parent 141d4ed6c0
commit 79fb7bc667
1 changed files with 121 additions and 28 deletions
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149
libavcodec/h264.c
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@@ -2522,8 +2522,8 @@ static int field_end(H264Context *h, int in_setup){
s->mb_y= 0;
if (!in_setup && !s->dropable)
ff_thread_report_progress((AVFrame*)s->current_picture_ptr, (16*s->mb_height >> FIELD_PICTURE) - 1,
s->picture_structure==PICT_BOTTOM_FIELD);
ff_thread_report_progress(&s->current_picture_ptr->f, INT_MAX,
s->picture_structure == PICT_BOTTOM_FIELD);
if (CONFIG_H264_VDPAU_DECODER && s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
ff_vdpau_h264_set_reference_frames(s);
@@ -2640,9 +2640,7 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
int num_ref_idx_active_override_flag;
unsigned int slice_type, tmp, i, j;
int default_ref_list_done = 0;
int last_pic_structure;
s->dropable= h->nal_ref_idc == 0;
int last_pic_structure, last_pic_dropable;
/* FIXME: 2tap qpel isn't implemented for high bit depth. */
if((s->avctx->flags2 & CODEC_FLAG2_FAST) && !h->nal_ref_idc && !h->pixel_shift){
@@ -2661,8 +2659,14 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
}
h0->current_slice = 0;
if (!s0->first_field)
s->current_picture_ptr= NULL;
if (!s0->first_field) {
if (s->current_picture_ptr && !s->dropable &&
s->current_picture_ptr->owner2 == s) {
ff_thread_report_progress(&s->current_picture_ptr->f, INT_MAX,
s->picture_structure == PICT_BOTTOM_FIELD);
}
s->current_picture_ptr = NULL;
}
}
slice_type= get_ue_golomb_31(&s->gb);
@@ -2862,6 +2866,8 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
h->mb_mbaff = 0;
h->mb_aff_frame = 0;
last_pic_structure = s0->picture_structure;
last_pic_dropable = s->dropable;
s->dropable = h->nal_ref_idc == 0;
if(h->sps.frame_mbs_only_flag){
s->picture_structure= PICT_FRAME;
}else{
@@ -2874,10 +2880,22 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
}
h->mb_field_decoding_flag= s->picture_structure != PICT_FRAME;
if(h0->current_slice == 0){
// Shorten frame num gaps so we don't have to allocate reference frames just to throw them away
if(h->frame_num != h->prev_frame_num) {
int unwrap_prev_frame_num = h->prev_frame_num, max_frame_num = 1<<h->sps.log2_max_frame_num;
if (h0->current_slice != 0) {
if (last_pic_structure != s->picture_structure ||
last_pic_dropable != s->dropable) {
av_log(h->s.avctx, AV_LOG_ERROR,
"Changing field mode (%d -> %d) between slices is not allowed\n",
last_pic_structure, s->picture_structure);
s->picture_structure = last_pic_structure;
s->dropable = last_pic_dropable;
return AVERROR_INVALIDDATA;
}
} else {
/* Shorten frame num gaps so we don't have to allocate reference
* frames just to throw them away */
if (h->frame_num != h->prev_frame_num) {
int unwrap_prev_frame_num = h->prev_frame_num;
int max_frame_num = 1 << h->sps.log2_max_frame_num;
if (unwrap_prev_frame_num > h->frame_num) unwrap_prev_frame_num -= max_frame_num;
@@ -2890,8 +2908,74 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
}
}
while(h->frame_num != h->prev_frame_num &&
h->frame_num != (h->prev_frame_num+1)%(1<<h->sps.log2_max_frame_num)){
/* See if we have a decoded first field looking for a pair...
* Here, we're using that to see if we should mark previously
* 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 (s0->first_field) {
assert(s0->current_picture_ptr);
assert(s0->current_picture_ptr->f.data[0]);
assert(s0->current_picture_ptr->f.reference != DELAYED_PIC_REF);
/* Mark old field/frame as completed */
if (!last_pic_dropable && s0->current_picture_ptr->owner2 == s0) {
ff_thread_report_progress(&s0->current_picture_ptr->f, INT_MAX,
last_pic_structure == PICT_BOTTOM_FIELD);
}
/* figure out if we have a complementary field pair */
if (!FIELD_PICTURE || s->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_dropable && last_pic_structure != PICT_FRAME) {
ff_thread_report_progress(&s0->current_picture_ptr->f, INT_MAX,
last_pic_structure == PICT_TOP_FIELD);
}
} else {
if (s0->current_picture_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_dropable && last_pic_structure != PICT_FRAME) {
ff_thread_report_progress(&s0->current_picture_ptr->f, INT_MAX,
last_pic_structure == PICT_TOP_FIELD);
}
} else {
/* Second field in complementary pair */
if (!((last_pic_structure == PICT_TOP_FIELD &&
s->picture_structure == PICT_BOTTOM_FIELD) ||
(last_pic_structure == PICT_BOTTOM_FIELD &&
s->picture_structure == PICT_TOP_FIELD))) {
av_log(s->avctx, AV_LOG_ERROR,
"Invalid field mode combination %d/%d\n",
last_pic_structure, s->picture_structure);
s->picture_structure = last_pic_structure;
s->dropable = last_pic_dropable;
return AVERROR_INVALIDDATA;
} else if (last_pic_dropable != s->dropable) {
av_log(s->avctx, AV_LOG_ERROR,
"Cannot combine reference and non-reference fields in the same frame\n");
av_log_ask_for_sample(s->avctx, NULL);
s->picture_structure = last_pic_structure;
s->dropable = last_pic_dropable;
return AVERROR_INVALIDDATA;
}
/* Take ownership of this buffer. Note that if another thread owned
* the first field of this buffer, we're not operating on that pointer,
* so the original thread is still responsible for reporting progress
* on that first field (or if that was us, we just did that above).
* By taking ownership, we assign responsibility to ourselves to
* report progress on the second field. */
s0->current_picture_ptr->owner2 = s0;
}
}
}
while (h->frame_num != h->prev_frame_num &&
h->frame_num != (h->prev_frame_num + 1) % (1 << h->sps.log2_max_frame_num)) {
Picture *prev = h->short_ref_count ? h->short_ref[0] : NULL;
av_log(h->s.avctx, AV_LOG_DEBUG, "Frame num gap %d %d\n", h->frame_num, h->prev_frame_num);
if (ff_h264_frame_start(h) < 0)
@@ -2922,7 +3006,9 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
}
}
/* See if we have a decoded first field looking for a pair... */
/* 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 (s0->first_field) {
assert(s0->current_picture_ptr);
assert(s0->current_picture_ptr->f.data[0]);
@@ -2938,16 +3024,11 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
s0->first_field = FIELD_PICTURE;
} else {
if (h->nal_ref_idc &&
s0->current_picture_ptr->f.reference &&
s0->current_picture_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.
*/
s0->first_field = 1;
if (s0->current_picture_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. */
s0->first_field = 1;
s0->current_picture_ptr = NULL;
} else {
@@ -3803,8 +3884,9 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
hx = h->thread_context[context_count];
ptr= ff_h264_decode_nal(hx, buf + buf_index, &dst_length, &consumed, next_avc - buf_index);
if (ptr==NULL || dst_length < 0){
return -1;
if (ptr == NULL || dst_length < 0) {
buf_index = -1;
goto end;
}
i= buf_index + consumed;
if((s->workaround_bugs & FF_BUG_AUTODETECT) && i+3<next_avc &&
@@ -3856,7 +3938,8 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
case NAL_IDR_SLICE:
if (h->nal_unit_type != NAL_IDR_SLICE) {
av_log(h->s.avctx, AV_LOG_ERROR, "Invalid mix of idr and non-idr slices");
return -1;
buf_index = -1;
goto end;
}
idr(h); // FIXME ensure we don't lose some frames if there is reordering
case NAL_SLICE:
@@ -3962,7 +4045,8 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
dsputil_init(&s->dsp, s->avctx);
} else {
av_log(avctx, AV_LOG_ERROR, "Unsupported bit depth: %d\n", h->sps.bit_depth_luma);
return -1;
buf_index = -1;
goto end;
}
}
break;
@@ -4004,6 +4088,15 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
}
if(context_count)
execute_decode_slices(h, context_count);
end:
/* clean up */
if (s->current_picture_ptr && s->current_picture_ptr->owner2 == s &&
!s->dropable) {
ff_thread_report_progress(&s->current_picture_ptr->f, INT_MAX,
s->picture_structure == PICT_BOTTOM_FIELD);
}
return buf_index;
}