]> git.sesse.net Git - ffmpeg/blobdiff - libavcodec/h264_parser.c
rv40: don't always do the full prev_type search
[ffmpeg] / libavcodec / h264_parser.c
index 73b156964c3a9440eb39c1548541c9df86abbfce..48215c5ada4966ccd7be83e2121dde6e2f930551 100644 (file)
@@ -2,36 +2,37 @@
  * H.26L/H.264/AVC/JVT/14496-10/... parser
  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
- * @file h264_parser.c
+ * @file
  * H.264 / AVC / MPEG4 part10 parser.
  * @author Michael Niedermayer <michaelni@gmx.at>
  */
 
 #include "parser.h"
-#include "h264_parser.h"
+#include "h264data.h"
+#include "golomb.h"
 
 #include <assert.h>
 
 
-int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
+static int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
 {
     int i;
     uint32_t state;
@@ -44,6 +45,18 @@ int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
 
     for(i=0; i<buf_size; i++){
         if(state==7){
+#if HAVE_FAST_UNALIGNED
+        /* we check i<buf_size instead of i+3/7 because its simpler
+         * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end
+         */
+#    if HAVE_FAST_64BIT
+            while(i<buf_size && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL))
+                i+=8;
+#    else
+            while(i<buf_size && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U))
+                i+=4;
+#    endif
+#endif
             for(; i<buf_size; i++){
                 if(!buf[i]){
                     state=2;
@@ -56,7 +69,7 @@ int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
             else            state>>=1; //2->1, 1->0, 0->0
         }else if(state<=5){
             int v= buf[i] & 0x1F;
-            if(v==7 || v==8 || v==9){
+            if(v==6 || v==7 || v==8 || v==9){
                 if(pc->frame_start_found){
                     i++;
                     goto found;
@@ -84,6 +97,147 @@ found:
     return i-(state&5);
 }
 
+/**
+ * Parse NAL units of found picture and decode some basic information.
+ *
+ * @param s parser context.
+ * @param avctx codec context.
+ * @param buf buffer with field/frame data.
+ * @param buf_size size of the buffer.
+ */
+static inline int parse_nal_units(AVCodecParserContext *s,
+                                  AVCodecContext *avctx,
+                                  const uint8_t *buf, int buf_size)
+{
+    H264Context *h = s->priv_data;
+    const uint8_t *buf_end = buf + buf_size;
+    unsigned int pps_id;
+    unsigned int slice_type;
+    int state = -1;
+    const uint8_t *ptr;
+
+    /* set some sane default values */
+    s->pict_type = AV_PICTURE_TYPE_I;
+    s->key_frame = 0;
+
+    h->s.avctx= avctx;
+    h->sei_recovery_frame_cnt = -1;
+    h->sei_dpb_output_delay         =  0;
+    h->sei_cpb_removal_delay        = -1;
+    h->sei_buffering_period_present =  0;
+
+    if (!buf_size)
+        return 0;
+
+    for(;;) {
+        int src_length, dst_length, consumed;
+        buf = avpriv_mpv_find_start_code(buf, buf_end, &state);
+        if(buf >= buf_end)
+            break;
+        --buf;
+        src_length = buf_end - buf;
+        switch (state & 0x1f) {
+        case NAL_SLICE:
+        case NAL_IDR_SLICE:
+            // Do not walk the whole buffer just to decode slice header
+            if (src_length > 20)
+                src_length = 20;
+            break;
+        }
+        ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
+        if (ptr==NULL || dst_length < 0)
+            break;
+
+        init_get_bits(&h->s.gb, ptr, 8*dst_length);
+        switch(h->nal_unit_type) {
+        case NAL_SPS:
+            ff_h264_decode_seq_parameter_set(h);
+            break;
+        case NAL_PPS:
+            ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
+            break;
+        case NAL_SEI:
+            ff_h264_decode_sei(h);
+            break;
+        case NAL_IDR_SLICE:
+            s->key_frame = 1;
+            /* fall through */
+        case NAL_SLICE:
+            get_ue_golomb(&h->s.gb);  // skip first_mb_in_slice
+            slice_type = get_ue_golomb_31(&h->s.gb);
+            s->pict_type = golomb_to_pict_type[slice_type % 5];
+            if (h->sei_recovery_frame_cnt >= 0) {
+                /* key frame, since recovery_frame_cnt is set */
+                s->key_frame = 1;
+            }
+            pps_id= get_ue_golomb(&h->s.gb);
+            if(pps_id>=MAX_PPS_COUNT) {
+                av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n");
+                return -1;
+            }
+            if(!h->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];
+            if(!h->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->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num);
+
+            avctx->profile = ff_h264_get_profile(&h->sps);
+            avctx->level   = h->sps.level_idc;
+
+            if(h->sps.frame_mbs_only_flag){
+                h->s.picture_structure= PICT_FRAME;
+            }else{
+                if(get_bits1(&h->s.gb)) { //field_pic_flag
+                    h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag
+                } else {
+                    h->s.picture_structure= PICT_FRAME;
+                }
+            }
+
+            if(h->sps.pic_struct_present_flag) {
+                switch (h->sei_pic_struct) {
+                    case SEI_PIC_STRUCT_TOP_FIELD:
+                    case SEI_PIC_STRUCT_BOTTOM_FIELD:
+                        s->repeat_pict = 0;
+                        break;
+                    case SEI_PIC_STRUCT_FRAME:
+                    case SEI_PIC_STRUCT_TOP_BOTTOM:
+                    case SEI_PIC_STRUCT_BOTTOM_TOP:
+                        s->repeat_pict = 1;
+                        break;
+                    case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
+                    case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
+                        s->repeat_pict = 2;
+                        break;
+                    case SEI_PIC_STRUCT_FRAME_DOUBLING:
+                        s->repeat_pict = 3;
+                        break;
+                    case SEI_PIC_STRUCT_FRAME_TRIPLING:
+                        s->repeat_pict = 5;
+                        break;
+                    default:
+                        s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
+                        break;
+                }
+            } else {
+                s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0;
+            }
+
+            return 0; /* no need to evaluate the rest */
+        }
+        buf += consumed;
+    }
+    /* didn't find a picture! */
+    av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
+    return -1;
+}
+
 static int h264_parse(AVCodecParserContext *s,
                       AVCodecContext *avctx,
                       const uint8_t **poutbuf, int *poutbuf_size,
@@ -93,6 +247,21 @@ static int h264_parse(AVCodecParserContext *s,
     ParseContext *pc = &h->s.parse_context;
     int next;
 
+    if (!h->got_first) {
+        h->got_first = 1;
+        if (avctx->extradata_size) {
+            h->s.avctx = avctx;
+            // must be done like in the decoder.
+            // otherwise opening the parser, creating extradata,
+            // and then closing and opening again
+            // will cause has_b_frames to be always set.
+            // NB: estimate_timings_from_pts behaves exactly like this.
+            if (!avctx->has_b_frames)
+                h->s.low_delay = 1;
+            ff_h264_decode_extradata(h);
+        }
+    }
+
     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
         next= buf_size;
     }else{
@@ -110,6 +279,22 @@ static int h264_parse(AVCodecParserContext *s,
         }
     }
 
+    parse_nal_units(s, avctx, buf, buf_size);
+
+    if (h->sei_cpb_removal_delay >= 0) {
+        s->dts_sync_point    = h->sei_buffering_period_present;
+        s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
+        s->pts_dts_delta     = h->sei_dpb_output_delay;
+    } else {
+        s->dts_sync_point    = INT_MIN;
+        s->dts_ref_dts_delta = INT_MIN;
+        s->pts_dts_delta     = INT_MIN;
+    }
+
+    if (s->flags & PARSER_FLAG_ONCE) {
+        s->flags &= PARSER_FLAG_COMPLETE_FRAMES;
+    }
+
     *poutbuf = buf;
     *poutbuf_size = buf_size;
     return next;
@@ -139,12 +324,28 @@ static int h264_split(AVCodecContext *avctx,
     return 0;
 }
 
+static void close(AVCodecParserContext *s)
+{
+    H264Context *h = s->priv_data;
+    ParseContext *pc = &h->s.parse_context;
+
+    av_free(pc->buffer);
+    ff_h264_free_context(h);
+}
+
+static int init(AVCodecParserContext *s)
+{
+    H264Context *h = s->priv_data;
+    h->thread_context[0] = h;
+    h->s.slice_context_count = 1;
+    return 0;
+}
 
-AVCodecParser h264_parser = {
-    { CODEC_ID_H264 },
-    sizeof(H264Context),
-    NULL,
-    h264_parse,
-    ff_parse_close,
-    h264_split,
+AVCodecParser ff_h264_parser = {
+    .codec_ids      = { CODEC_ID_H264 },
+    .priv_data_size = sizeof(H264Context),
+    .parser_init    = init,
+    .parser_parse   = h264_parse,
+    .parser_close   = close,
+    .split          = h264_split,
 };