Commit afebe2f7 authored by Andreas Öman's avatar Andreas Öman Committed by Guillaume Poirier
Browse files

Add slice-based parallel H.264 decoding

Patch by Andreas Öman % andreas A olebyn P nu %
NB: depends on having a thread library activated at config time, and on
having a source encoded with multiple slices
Original threads:
date: May 18, 2007 11:00 PM
subject: [FFmpeg-devel] Parallelized h264 proof-of-concept
date: Jun 15, 2007 10:10 PM
subject: [FFmpeg-devel] [PATCH] h264 parallelized, (was: Parallelized h264 proof-of-concept)
date: Jun 25, 2007 7:02 PM
subject: Re: [FFmpeg-devel] [PATCH] h264 parallelized

Originally committed as revision 10407 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent e146ce52
......@@ -2005,6 +2005,7 @@ static void decode_init_vlc(void){
static void free_tables(H264Context *h){
int i;
H264Context *hx;
av_freep(&h->intra4x4_pred_mode);
av_freep(&h->chroma_pred_mode_table);
av_freep(&h->cbp_table);
......@@ -2013,20 +2014,25 @@ static void free_tables(H264Context *h){
av_freep(&h->direct_table);
av_freep(&h->non_zero_count);
av_freep(&h->slice_table_base);
av_freep(&h->top_borders[1]);
av_freep(&h->top_borders[0]);
h->slice_table= NULL;
av_freep(&h->mb2b_xy);
av_freep(&h->mb2b8_xy);
av_freep(&h->s.obmc_scratchpad);
for(i = 0; i < MAX_SPS_COUNT; i++)
av_freep(h->sps_buffers + i);
for(i = 0; i < MAX_PPS_COUNT; i++)
av_freep(h->pps_buffers + i);
for(i = 0; i < h->s.avctx->thread_count; i++) {
hx = h->thread_context[i];
if(!hx) continue;
av_freep(&hx->top_borders[1]);
av_freep(&hx->top_borders[0]);
av_freep(&hx->s.obmc_scratchpad);
av_freep(&hx->s.allocated_edge_emu_buffer);
}
}
static void init_dequant8_coeff_table(H264Context *h){
......@@ -2107,8 +2113,6 @@ static int alloc_tables(H264Context *h){
CHECKED_ALLOCZ(h->non_zero_count , big_mb_num * 16 * sizeof(uint8_t))
CHECKED_ALLOCZ(h->slice_table_base , (big_mb_num+s->mb_stride) * sizeof(uint8_t))
CHECKED_ALLOCZ(h->top_borders[0] , s->mb_width * (16+8+8) * sizeof(uint8_t))
CHECKED_ALLOCZ(h->top_borders[1] , s->mb_width * (16+8+8) * sizeof(uint8_t))
CHECKED_ALLOCZ(h->cbp_table, big_mb_num * sizeof(uint16_t))
if( h->pps.cabac ) {
......@@ -2145,6 +2149,47 @@ fail:
return -1;
}
/**
* Mimic alloc_tables(), but for every context thread.
*/
static void clone_tables(H264Context *dst, H264Context *src){
dst->intra4x4_pred_mode = src->intra4x4_pred_mode;
dst->non_zero_count = src->non_zero_count;
dst->slice_table = src->slice_table;
dst->cbp_table = src->cbp_table;
dst->mb2b_xy = src->mb2b_xy;
dst->mb2b8_xy = src->mb2b8_xy;
dst->chroma_pred_mode_table = src->chroma_pred_mode_table;
dst->mvd_table[0] = src->mvd_table[0];
dst->mvd_table[1] = src->mvd_table[1];
dst->direct_table = src->direct_table;
if(!dst->dequant4_coeff[0])
init_dequant_tables(dst);
dst->s.obmc_scratchpad = NULL;
ff_h264_pred_init(&dst->hpc, src->s.codec_id);
dst->dequant_coeff_pps= -1;
}
/**
* Init context
* Allocate buffers which are not shared amongst multiple threads.
*/
static int context_init(H264Context *h){
MpegEncContext * const s = &h->s;
CHECKED_ALLOCZ(h->top_borders[0], h->s.mb_width * (16+8+8) * sizeof(uint8_t))
CHECKED_ALLOCZ(h->top_borders[1], h->s.mb_width * (16+8+8) * sizeof(uint8_t))
// edge emu needs blocksize + filter length - 1 (=17x17 for halfpel / 21x21 for h264)
CHECKED_ALLOCZ(s->allocated_edge_emu_buffer,
(s->width+64)*2*21*2); //(width + edge + align)*interlaced*MBsize*tolerance
s->edge_emu_buffer= s->allocated_edge_emu_buffer + (s->width+64)*2*21;
return 0;
fail:
return -1; // free_tables will clean up for us
}
static void common_init(H264Context *h){
MpegEncContext * const s = &h->s;
......@@ -2190,6 +2235,7 @@ static int decode_init(AVCodecContext *avctx){
h->is_avc = 0;
}
h->thread_context[0] = h;
return 0;
}
......@@ -2216,11 +2262,12 @@ static int frame_start(H264Context *h){
/* can't be in alloc_tables because linesize isn't known there.
* FIXME: redo bipred weight to not require extra buffer? */
if(!s->obmc_scratchpad)
s->obmc_scratchpad = av_malloc(16*2*s->linesize + 8*2*s->uvlinesize);
for(i = 0; i < s->avctx->thread_count; i++)
if(!h->thread_context[i]->s.obmc_scratchpad)
h->thread_context[i]->s.obmc_scratchpad = av_malloc(16*2*s->linesize + 8*2*s->uvlinesize);
/* some macroblocks will be accessed before they're available */
if(FRAME_MBAFF)
if(FRAME_MBAFF || s->avctx->thread_count > 1)
memset(h->slice_table, -1, (s->mb_height*s->mb_stride-1) * sizeof(uint8_t));
// s->decode= (s->flags&CODEC_FLAG_PSNR) || !s->encoding || s->current_picture.reference /*|| h->contains_intra*/ || 1;
......@@ -3453,17 +3500,46 @@ static void init_scan_tables(H264Context *h){
h->field_scan8x8_cavlc_q0 = h->field_scan8x8_cavlc;
}
}
/**
* Replicates H264 "master" context to thread contexts.
*/
static void clone_slice(H264Context *dst, H264Context *src)
{
memcpy(dst->block_offset, src->block_offset, sizeof(dst->block_offset));
dst->s.current_picture_ptr = src->s.current_picture_ptr;
dst->s.current_picture = src->s.current_picture;
dst->s.linesize = src->s.linesize;
dst->s.uvlinesize = src->s.uvlinesize;
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->ref_list, src->ref_list, sizeof(dst->ref_list));
}
/**
* decodes a slice header.
* this will allso call MPV_common_init() and 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 occured, 1 if decoding must not be multithreaded
*/
static int decode_slice_header(H264Context *h){
static int decode_slice_header(H264Context *h, H264Context *h0){
MpegEncContext * const s = &h->s;
unsigned int first_mb_in_slice;
unsigned int pps_id;
int num_ref_idx_active_override_flag;
static const uint8_t slice_type_map[5]= {P_TYPE, B_TYPE, I_TYPE, SP_TYPE, SI_TYPE};
unsigned int slice_type, tmp;
unsigned int slice_type, tmp, i;
int default_ref_list_done = 0;
s->current_picture.reference= h->nal_ref_idc != 0;
......@@ -3472,7 +3548,7 @@ static int decode_slice_header(H264Context *h){
first_mb_in_slice= get_ue_golomb(&s->gb);
if((s->flags2 & CODEC_FLAG2_CHUNKS) && first_mb_in_slice == 0){
h->slice_num = 0;
h0->current_slice = 0;
s->current_picture_ptr= NULL;
}
......@@ -3489,7 +3565,7 @@ static int decode_slice_header(H264Context *h){
slice_type= slice_type_map[ slice_type ];
if (slice_type == I_TYPE
|| (h->slice_num != 0 && slice_type == h->slice_type) ) {
|| (h0->current_slice != 0 && slice_type == h0->last_slice_type) ) {
default_ref_list_done = 1;
}
h->slice_type= slice_type;
......@@ -3501,17 +3577,17 @@ static int decode_slice_header(H264Context *h){
av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
return -1;
}
if(!h->pps_buffers[pps_id]) {
if(!h0->pps_buffers[pps_id]) {
av_log(h->s.avctx, AV_LOG_ERROR, "non existing PPS referenced\n");
return -1;
}
h->pps= *h->pps_buffers[pps_id];
h->pps= *h0->pps_buffers[pps_id];
if(!h->sps_buffers[h->pps.sps_id]) {
if(!h0->sps_buffers[h->pps.sps_id]) {
av_log(h->s.avctx, AV_LOG_ERROR, "non existing SPS referenced\n");
return -1;
}
h->sps = *h->sps_buffers[h->pps.sps_id];
h->sps = *h0->sps_buffers[h->pps.sps_id];
if(h->dequant_coeff_pps != pps_id){
h->dequant_coeff_pps = pps_id;
......@@ -3532,16 +3608,35 @@ static int decode_slice_header(H264Context *h){
if (s->context_initialized
&& ( s->width != s->avctx->width || s->height != s->avctx->height)) {
if(h != h0)
return -1; // width / height changed during parallelized decoding
free_tables(h);
MPV_common_end(s);
}
if (!s->context_initialized) {
if(h != h0)
return -1; // we cant (re-)initialize context during parallel decoding
if (MPV_common_init(s) < 0)
return -1;
init_scan_tables(h);
alloc_tables(h);
for(i = 1; i < s->avctx->thread_count; i++) {
H264Context *c;
c = h->thread_context[i] = av_malloc(sizeof(H264Context));
memcpy(c, h, sizeof(MpegEncContext));
memset(&c->s + 1, 0, sizeof(H264Context) - sizeof(MpegEncContext));
c->sps = h->sps;
c->pps = h->pps;
init_scan_tables(c);
clone_tables(c, h);
}
for(i = 0; i < s->avctx->thread_count; i++)
if(context_init(h->thread_context[i]) < 0)
return -1;
s->avctx->width = s->width;
s->avctx->height = s->height;
s->avctx->sample_aspect_ratio= h->sps.sar;
......@@ -3557,10 +3652,12 @@ static int decode_slice_header(H264Context *h){
}
}
if(h->slice_num == 0){
if(h0->current_slice == 0){
if(frame_start(h) < 0)
return -1;
}
if(h != h0)
clone_slice(h, h0);
s->current_picture_ptr->frame_num= //FIXME frame_num cleanup
h->frame_num= get_bits(&s->gb, h->sps.log2_max_frame_num);
......@@ -3667,7 +3764,7 @@ static int decode_slice_header(H264Context *h){
h->use_weight = 0;
if(s->current_picture.reference)
decode_ref_pic_marking(h, &s->gb);
decode_ref_pic_marking(h0, &s->gb);
if(FRAME_MBAFF)
fill_mbaff_ref_list(h);
......@@ -3716,6 +3813,17 @@ static int decode_slice_header(H264Context *h){
h->slice_beta_offset = get_se_golomb(&s->gb) << 1;
}
}
if(h->deblocking_filter == 1 && h0->max_contexts > 1) {
h0->max_contexts = 1;
if(!h0->single_decode_warning) {
av_log(s->avctx, AV_LOG_INFO, "Cannot parallelize deblocking type 1, decoding such frames in sequential order\n");
h0->single_decode_warning = 1;
}
if(h != h0)
return 1; // deblocking switched inside frame
}
if( s->avctx->skip_loop_filter >= AVDISCARD_ALL
||(s->avctx->skip_loop_filter >= AVDISCARD_NONKEY && h->slice_type != I_TYPE)
||(s->avctx->skip_loop_filter >= AVDISCARD_BIDIR && h->slice_type == B_TYPE)
......@@ -3727,7 +3835,8 @@ static int decode_slice_header(H264Context *h){
slice_group_change_cycle= get_bits(&s->gb, ?);
#endif
h->slice_num++;
h0->last_slice_type = slice_type;
h->slice_num = ++h0->current_slice;
h->emu_edge_width= (s->flags&CODEC_FLAG_EMU_EDGE) ? 0 : 16;
h->emu_edge_height= FRAME_MBAFF ? 0 : h->emu_edge_width;
......@@ -6295,7 +6404,7 @@ static void filter_mb( H264Context *h, int mb_x, int mb_y, uint8_t *img_y, uint8
}
}
static int decode_slice(H264Context *h){
static int decode_slice(struct AVCodecContext *avctx, H264Context *h){
MpegEncContext * const s = &h->s;
const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
......@@ -6940,10 +7049,48 @@ static inline int decode_picture_parameter_set(H264Context *h, int bit_length){
return 0;
}
/**
* Call decode_slice() for each context.
*
* @param h h264 master context
* @param context_count number of contexts to execute
*/
static void execute_decode_slices(H264Context *h, int context_count){
MpegEncContext * const s = &h->s;
AVCodecContext * const avctx= s->avctx;
H264Context *hx;
int i;
if(context_count == 1) {
decode_slice(avctx, h);
} else {
for(i = 1; i < context_count; i++) {
hx = h->thread_context[i];
hx->s.error_resilience = avctx->error_resilience;
hx->s.error_count = 0;
}
avctx->execute(avctx, (void *)decode_slice,
(void **)h->thread_context, NULL, context_count);
/* pull back stuff from slices to master context */
hx = h->thread_context[context_count - 1];
s->mb_x = hx->s.mb_x;
s->mb_y = hx->s.mb_y;
for(i = 1; i < context_count; i++)
h->s.error_count += h->thread_context[i]->s.error_count;
}
}
static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
MpegEncContext * const s = &h->s;
AVCodecContext * const avctx= s->avctx;
int buf_index=0;
H264Context *hx; ///< thread context
int context_count = 0;
h->max_contexts = avctx->thread_count;
#if 0
int i;
for(i=0; i<50; i++){
......@@ -6951,7 +7098,7 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
}
#endif
if(!(s->flags2 & CODEC_FLAG2_CHUNKS)){
h->slice_num = 0;
h->current_slice = 0;
s->current_picture_ptr= NULL;
}
......@@ -6961,6 +7108,7 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
int bit_length;
uint8_t *ptr;
int i, nalsize = 0;
int err;
if(h->is_avc) {
if(buf_index >= buf_size) break;
......@@ -6989,7 +7137,9 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
buf_index+=3;
}
ptr= decode_nal(h, buf + buf_index, &dst_length, &consumed, h->is_avc ? nalsize : buf_size - buf_index);
hx = h->thread_context[context_count];
ptr= decode_nal(hx, buf + buf_index, &dst_length, &consumed, h->is_avc ? nalsize : buf_size - buf_index);
if (ptr==NULL || dst_length < 0){
return -1;
}
......@@ -6998,7 +7148,7 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
bit_length= !dst_length ? 0 : (8*dst_length - decode_rbsp_trailing(h, ptr + dst_length - 1));
if(s->avctx->debug&FF_DEBUG_STARTCODE){
av_log(h->s.avctx, AV_LOG_DEBUG, "NAL %d at %d/%d length %d\n", h->nal_unit_type, buf_index, buf_size, dst_length);
av_log(h->s.avctx, AV_LOG_DEBUG, "NAL %d at %d/%d length %d\n", hx->nal_unit_type, buf_index, buf_size, dst_length);
}
if (h->is_avc && (nalsize != consumed))
......@@ -7010,53 +7160,56 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
||(avctx->skip_frame >= AVDISCARD_NONREF && h->nal_ref_idc == 0))
continue;
switch(h->nal_unit_type){
again:
err = 0;
switch(hx->nal_unit_type){
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;
}
idr(h); //FIXME ensure we don't loose some frames if there is reordering
case NAL_SLICE:
init_get_bits(&s->gb, ptr, bit_length);
h->intra_gb_ptr=
h->inter_gb_ptr= &s->gb;
s->data_partitioning = 0;
if(decode_slice_header(h) < 0){
av_log(h->s.avctx, AV_LOG_ERROR, "decode_slice_header error\n");
break;
}
s->current_picture_ptr->key_frame= (h->nal_unit_type == NAL_IDR_SLICE);
if(h->redundant_pic_count==0 && s->hurry_up < 5
&& (avctx->skip_frame < AVDISCARD_NONREF || h->nal_ref_idc)
&& (avctx->skip_frame < AVDISCARD_BIDIR || h->slice_type!=B_TYPE)
&& (avctx->skip_frame < AVDISCARD_NONKEY || h->slice_type==I_TYPE)
init_get_bits(&hx->s.gb, ptr, bit_length);
hx->intra_gb_ptr=
hx->inter_gb_ptr= &hx->s.gb;
hx->s.data_partitioning = 0;
if((err = decode_slice_header(hx, h)))
break;
s->current_picture_ptr->key_frame= (hx->nal_unit_type == NAL_IDR_SLICE);
if(hx->redundant_pic_count==0 && hx->s.hurry_up < 5
&& (avctx->skip_frame < AVDISCARD_NONREF || hx->nal_ref_idc)
&& (avctx->skip_frame < AVDISCARD_BIDIR || hx->slice_type!=B_TYPE)
&& (avctx->skip_frame < AVDISCARD_NONKEY || hx->slice_type==I_TYPE)
&& avctx->skip_frame < AVDISCARD_ALL)
decode_slice(h);
context_count++;
break;
case NAL_DPA:
init_get_bits(&s->gb, ptr, bit_length);
h->intra_gb_ptr=
h->inter_gb_ptr= NULL;
s->data_partitioning = 1;
init_get_bits(&hx->s.gb, ptr, bit_length);
hx->intra_gb_ptr=
hx->inter_gb_ptr= NULL;
hx->s.data_partitioning = 1;
if(decode_slice_header(h) < 0){
av_log(h->s.avctx, AV_LOG_ERROR, "decode_slice_header error\n");
}
err = decode_slice_header(hx, h);
break;
case NAL_DPB:
init_get_bits(&h->intra_gb, ptr, bit_length);
h->intra_gb_ptr= &h->intra_gb;
init_get_bits(&hx->intra_gb, ptr, bit_length);
hx->intra_gb_ptr= &hx->intra_gb;
break;
case NAL_DPC:
init_get_bits(&h->inter_gb, ptr, bit_length);
h->inter_gb_ptr= &h->inter_gb;
init_get_bits(&hx->inter_gb, ptr, bit_length);
hx->inter_gb_ptr= &hx->inter_gb;
if(h->redundant_pic_count==0 && h->intra_gb_ptr && s->data_partitioning
if(hx->redundant_pic_count==0 && hx->intra_gb_ptr && hx->s.data_partitioning
&& s->context_initialized
&& s->hurry_up < 5
&& (avctx->skip_frame < AVDISCARD_NONREF || h->nal_ref_idc)
&& (avctx->skip_frame < AVDISCARD_BIDIR || h->slice_type!=B_TYPE)
&& (avctx->skip_frame < AVDISCARD_NONKEY || h->slice_type==I_TYPE)
&& (avctx->skip_frame < AVDISCARD_NONREF || hx->nal_ref_idc)
&& (avctx->skip_frame < AVDISCARD_BIDIR || hx->slice_type!=B_TYPE)
&& (avctx->skip_frame < AVDISCARD_NONKEY || hx->slice_type==I_TYPE)
&& avctx->skip_frame < AVDISCARD_ALL)
decode_slice(h);
context_count++;
break;
case NAL_SEI:
init_get_bits(&s->gb, ptr, bit_length);
......@@ -7088,8 +7241,27 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
default:
av_log(avctx, AV_LOG_DEBUG, "Unknown NAL code: %d (%d bits)\n", h->nal_unit_type, bit_length);
}
}
if(context_count == h->max_contexts) {
execute_decode_slices(h, context_count);
context_count = 0;
}
if (err < 0)
av_log(h->s.avctx, AV_LOG_ERROR, "decode_slice_header error\n");
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 transfered, 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;
goto again;
}
}
if(context_count)
execute_decode_slices(h, context_count);
return buf_index;
}
......
......@@ -380,6 +380,35 @@ typedef struct H264Context{
const uint8_t *field_scan8x8_cavlc_q0;
int x264_build;
/**
* @defgroup multithreading Members for slice based multithreading
* @{
*/
struct H264Context *thread_context[MAX_THREADS];
/**
* current slice number, used to initalize slice_num of each thread/context
*/
int current_slice;
/**
* Max number of threads / contexts.
* This is equal to AVCodecContext.thread_count unless
* multithreaded decoding is impossible, in which case it is
* reduced to 1.
*/
int max_contexts;
/**
* 1 if the single thread fallback warning has already been
* displayed, 0 otherwise.
*/
int single_decode_warning;
int last_slice_type;
/** @} */
}H264Context;
#endif /* H264_H */
......@@ -418,7 +418,7 @@ void MPV_decode_defaults(MpegEncContext *s){
*/
int MPV_common_init(MpegEncContext *s)
{
int y_size, c_size, yc_size, i, mb_array_size, mv_table_size, x, y;
int y_size, c_size, yc_size, i, mb_array_size, mv_table_size, x, y, threads;
s->mb_height = (s->height + 15) / 16;
......@@ -587,12 +587,16 @@ int MPV_common_init(MpegEncContext *s)
s->context_initialized = 1;
s->thread_context[0]= s;
for(i=1; i<s->avctx->thread_count; i++){
/* h264 does thread context setup itself, but it needs context[0]
* to be fully initialized for the error resilience code */
threads = s->codec_id == CODEC_ID_H264 ? 1 : s->avctx->thread_count;
for(i=1; i<threads; i++){
s->thread_context[i]= av_malloc(sizeof(MpegEncContext));
memcpy(s->thread_context[i], s, sizeof(MpegEncContext));
}
for(i=0; i<s->avctx->thread_count; i++){
for(i=0; i<threads; i++){
if(init_duplicate_context(s->thread_context[i], s) < 0)
goto fail;
s->thread_context[i]->start_mb_y= (s->mb_height*(i ) + s->avctx->thread_count/2) / s->avctx->thread_count;
......
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