Split SEI code off h264.c.

Originally committed as revision 21168 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 206 insertions, 0 deletions

diff --git a/libavcodec/h264_sei.c b/libavcodec/h264_sei.c
new file mode 100644
index 0000000000..de0b19a673
--- /dev/null
+++ b/libavcodec/h264_sei.c
@@ -0,0 +1,206 @@
+/*
+ * H.26L/H.264/AVC/JVT/14496-10/... sei decoding
+ * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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,
+ * 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file libavcodec/h264-sei.c
+ * H.264 / AVC / MPEG4 part10 sei decoding.
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+#include "internal.h"
+#include "avcodec.h"
+#include "h264.h"
+#include "golomb.h"
+
+//#undef NDEBUG
+#include <assert.h>
+
+static const uint8_t sei_num_clock_ts_table[9]={
+    1,  1,  1,  2,  2,  3,  3,  2,  3
+};
+
+void ff_h264_reset_sei(H264Context *h) {
+    h->sei_recovery_frame_cnt       = -1;
+    h->sei_dpb_output_delay         =  0;
+    h->sei_cpb_removal_delay        = -1;
+    h->sei_buffering_period_present =  0;
+}
+
+static int decode_picture_timing(H264Context *h){
+    MpegEncContext * const s = &h->s;
+    if(h->sps.nal_hrd_parameters_present_flag || h->sps.vcl_hrd_parameters_present_flag){
+        h->sei_cpb_removal_delay = get_bits(&s->gb, h->sps.cpb_removal_delay_length);
+        h->sei_dpb_output_delay = get_bits(&s->gb, h->sps.dpb_output_delay_length);
+    }
+    if(h->sps.pic_struct_present_flag){
+        unsigned int i, num_clock_ts;
+        h->sei_pic_struct = get_bits(&s->gb, 4);
+        h->sei_ct_type    = 0;
+
+        if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
+            return -1;
+
+        num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
+
+        for (i = 0 ; i < num_clock_ts ; i++){
+            if(get_bits(&s->gb, 1)){                  /* clock_timestamp_flag */
+                unsigned int full_timestamp_flag;
+                h->sei_ct_type |= 1<<get_bits(&s->gb, 2);
+                skip_bits(&s->gb, 1);                 /* nuit_field_based_flag */
+                skip_bits(&s->gb, 5);                 /* counting_type */
+                full_timestamp_flag = get_bits(&s->gb, 1);
+                skip_bits(&s->gb, 1);                 /* discontinuity_flag */
+                skip_bits(&s->gb, 1);                 /* cnt_dropped_flag */
+                skip_bits(&s->gb, 8);                 /* n_frames */
+                if(full_timestamp_flag){
+                    skip_bits(&s->gb, 6);             /* seconds_value 0..59 */
+                    skip_bits(&s->gb, 6);             /* minutes_value 0..59 */
+                    skip_bits(&s->gb, 5);             /* hours_value 0..23 */
+                }else{
+                    if(get_bits(&s->gb, 1)){          /* seconds_flag */
+                        skip_bits(&s->gb, 6);         /* seconds_value range 0..59 */
+                        if(get_bits(&s->gb, 1)){      /* minutes_flag */
+                            skip_bits(&s->gb, 6);     /* minutes_value 0..59 */
+                            if(get_bits(&s->gb, 1))   /* hours_flag */
+                                skip_bits(&s->gb, 5); /* hours_value 0..23 */
+                        }
+                    }
+                }
+                if(h->sps.time_offset_length > 0)
+                    skip_bits(&s->gb, h->sps.time_offset_length); /* time_offset */
+            }
+        }
+
+        if(s->avctx->debug & FF_DEBUG_PICT_INFO)
+            av_log(s->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct);
+    }
+    return 0;
+}
+
+static int decode_unregistered_user_data(H264Context *h, int size){
+    MpegEncContext * const s = &h->s;
+    uint8_t user_data[16+256];
+    int e, build, i;
+
+    if(size<16)
+        return -1;
+
+    for(i=0; i<sizeof(user_data)-1 && i<size; i++){
+        user_data[i]= get_bits(&s->gb, 8);
+    }
+
+    user_data[i]= 0;
+    e= sscanf(user_data+16, "x264 - core %d"/*%s - H.264/MPEG-4 AVC codec - Copyleft 2005 - http://www.videolan.org/x264.html*/, &build);
+    if(e==1 && build>=0)
+        h->x264_build= build;
+
+    if(s->avctx->debug & FF_DEBUG_BUGS)
+        av_log(s->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data+16);
+
+    for(; i<size; i++)
+        skip_bits(&s->gb, 8);
+
+    return 0;
+}
+
+static int decode_recovery_point(H264Context *h){
+    MpegEncContext * const s = &h->s;
+
+    h->sei_recovery_frame_cnt = get_ue_golomb(&s->gb);
+    skip_bits(&s->gb, 4);       /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
+
+    return 0;
+}
+
+static int decode_buffering_period(H264Context *h){
+    MpegEncContext * const s = &h->s;
+    unsigned int sps_id;
+    int sched_sel_idx;
+    SPS *sps;
+
+    sps_id = get_ue_golomb_31(&s->gb);
+    if(sps_id > 31 || !h->sps_buffers[sps_id]) {
+        av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
+        return -1;
+    }
+    sps = h->sps_buffers[sps_id];
+
+    // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
+    if (sps->nal_hrd_parameters_present_flag) {
+        for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
+            h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&s->gb, sps->initial_cpb_removal_delay_length);
+            skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
+        }
+    }
+    if (sps->vcl_hrd_parameters_present_flag) {
+        for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
+            h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&s->gb, sps->initial_cpb_removal_delay_length);
+            skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
+        }
+    }
+
+    h->sei_buffering_period_present = 1;
+    return 0;
+}
+
+int ff_h264_decode_sei(H264Context *h){
+    MpegEncContext * const s = &h->s;
+
+    while(get_bits_count(&s->gb) + 16 < s->gb.size_in_bits){
+        int size, type;
+
+        type=0;
+        do{
+            type+= show_bits(&s->gb, 8);
+        }while(get_bits(&s->gb, 8) == 255);
+
+        size=0;
+        do{
+            size+= show_bits(&s->gb, 8);
+        }while(get_bits(&s->gb, 8) == 255);
+
+        switch(type){
+        case SEI_TYPE_PIC_TIMING: // Picture timing SEI
+            if(decode_picture_timing(h) < 0)
+                return -1;
+            break;
+        case SEI_TYPE_USER_DATA_UNREGISTERED:
+            if(decode_unregistered_user_data(h, size) < 0)
+                return -1;
+            break;
+        case SEI_TYPE_RECOVERY_POINT:
+            if(decode_recovery_point(h) < 0)
+                return -1;
+            break;
+        case SEI_BUFFERING_PERIOD:
+            if(decode_buffering_period(h) < 0)
+                return -1;
+            break;
+        default:
+            skip_bits(&s->gb, 8*size);
+        }
+
+        //FIXME check bits here
+        align_get_bits(&s->gb);
+    }
+
+    return 0;
+}