h264_sei: parse the picture timing SEIs correctly

Those SEIs refer to the currently active SPS. However, since the SEI
NALUs precede the coded picture data in the bitstream, the active SPS is
in general not known when we are decoding the SEI.

Therefore, store the content of the picture timing SEIs and actually
parse it when the active SPS is known.

diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c
index 5f9a9c46eff945d875e0a31c2cda029335626153..ec1cbc6a661aff181319394edaae46559e48240d 100644 (file)
--- a/libavcodec/h264_parser.c
+++ b/libavcodec/h264_parser.c
@@ -481,6 +481,15 @@ static inline int parse_nal_units(AVCodecParserContext *s,
                 }
             }
 
+            if (p->sei.picture_timing.present) {
+                ret = ff_h264_sei_process_picture_timing(&p->sei.picture_timing,
+                                                         sps, avctx);
+                if (ret < 0) {
+                    av_log(avctx, AV_LOG_ERROR, "Error processing the picture timing SEI\n");
+                    p->sei.picture_timing.present = 0;
+                }
+            }
+
             if (sps->pic_struct_present_flag && p->sei.picture_timing.present) {
                 switch (p->sei.picture_timing.pic_struct) {
                 case H264_SEI_PIC_STRUCT_TOP_FIELD:

diff --git a/libavcodec/h264_sei.c b/libavcodec/h264_sei.c
index 32d13985f3e445fb32670b5515b7446071896e04..870dd90717ecdd657f7d1f1d0e9cdb68423bccee 100644 (file)
--- a/libavcodec/h264_sei.c
+++ b/libavcodec/h264_sei.c
@@ -54,30 +54,22 @@ void ff_h264_sei_uninit(H264SEIContext *h)
     av_buffer_unref(&h->a53_caption.buf_ref);
 }
 
-static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
-                                 const H264ParamSets *ps, void *logctx)
+int ff_h264_sei_process_picture_timing(H264SEIPictureTiming *h, const SPS *sps,
+                                       void *logctx)
 {
-    int i;
-    const SPS *sps = ps->sps;
-
-    for (i = 0; i<MAX_SPS_COUNT; i++)
-        if ((!sps || !sps->log2_max_frame_num) && ps->sps_list[i])
-            sps = (const SPS *)ps->sps_list[i]->data;
+    GetBitContext gb;
 
-    if (!sps) {
-        av_log(logctx, AV_LOG_ERROR, "SPS unavailable in decode_picture_timing\n");
-        return AVERROR_PS_NOT_FOUND;
-    }
+    init_get_bits(&gb, h->payload, h->payload_size_bits);
 
     if (sps->nal_hrd_parameters_present_flag ||
         sps->vcl_hrd_parameters_present_flag) {
-        h->cpb_removal_delay = get_bits_long(gb, sps->cpb_removal_delay_length);
-        h->dpb_output_delay  = get_bits_long(gb, sps->dpb_output_delay_length);
+        h->cpb_removal_delay = get_bits_long(&gb, sps->cpb_removal_delay_length);
+        h->dpb_output_delay  = get_bits_long(&gb, sps->dpb_output_delay_length);
     }
     if (sps->pic_struct_present_flag) {
         unsigned int i, num_clock_ts;
 
-        h->pic_struct = get_bits(gb, 4);
+        h->pic_struct = get_bits(&gb, 4);
         h->ct_type    = 0;
 
         if (h->pic_struct > H264_SEI_PIC_STRUCT_FRAME_TRIPLING)
@@ -86,38 +78,38 @@ static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
         num_clock_ts = sei_num_clock_ts_table[h->pic_struct];
         h->timecode_cnt = 0;
         for (i = 0; i < num_clock_ts; i++) {
-            if (get_bits(gb, 1)) {                      /* clock_timestamp_flag */
+            if (get_bits(&gb, 1)) {                      /* clock_timestamp_flag */
                 H264SEITimeCode *tc = &h->timecode[h->timecode_cnt++];
                 unsigned int full_timestamp_flag;
                 unsigned int counting_type, cnt_dropped_flag;
-                h->ct_type |= 1 << get_bits(gb, 2);
-                skip_bits(gb, 1);                       /* nuit_field_based_flag */
-                counting_type = get_bits(gb, 5);        /* counting_type */
-                full_timestamp_flag = get_bits(gb, 1);
-                skip_bits(gb, 1);                       /* discontinuity_flag */
-                cnt_dropped_flag = get_bits(gb, 1);      /* cnt_dropped_flag */
+                h->ct_type |= 1 << get_bits(&gb, 2);
+                skip_bits(&gb, 1);                       /* nuit_field_based_flag */
+                counting_type = get_bits(&gb, 5);        /* counting_type */
+                full_timestamp_flag = get_bits(&gb, 1);
+                skip_bits(&gb, 1);                       /* discontinuity_flag */
+                cnt_dropped_flag = get_bits(&gb, 1);      /* cnt_dropped_flag */
                 if (cnt_dropped_flag && counting_type > 1 && counting_type < 7)
                     tc->dropframe = 1;
-                tc->frame = get_bits(gb, 8);         /* n_frames */
+                tc->frame = get_bits(&gb, 8);         /* n_frames */
                 if (full_timestamp_flag) {
                     tc->full = 1;
-                    tc->seconds = get_bits(gb, 6); /* seconds_value 0..59 */
-                    tc->minutes = get_bits(gb, 6); /* minutes_value 0..59 */
-                    tc->hours = get_bits(gb, 5);   /* hours_value 0..23 */
+                    tc->seconds = get_bits(&gb, 6); /* seconds_value 0..59 */
+                    tc->minutes = get_bits(&gb, 6); /* minutes_value 0..59 */
+                    tc->hours = get_bits(&gb, 5);   /* hours_value 0..23 */
                 } else {
                     tc->seconds = tc->minutes = tc->hours = tc->full = 0;
-                    if (get_bits(gb, 1)) {             /* seconds_flag */
-                        tc->seconds = get_bits(gb, 6);
-                        if (get_bits(gb, 1)) {         /* minutes_flag */
-                            tc->minutes = get_bits(gb, 6);
-                            if (get_bits(gb, 1))       /* hours_flag */
-                                tc->hours = get_bits(gb, 5);
+                    if (get_bits(&gb, 1)) {             /* seconds_flag */
+                        tc->seconds = get_bits(&gb, 6);
+                        if (get_bits(&gb, 1)) {         /* minutes_flag */
+                            tc->minutes = get_bits(&gb, 6);
+                            if (get_bits(&gb, 1))       /* hours_flag */
+                                tc->hours = get_bits(&gb, 5);
                         }
                     }
                 }
 
                 if (sps->time_offset_length > 0)
-                    skip_bits(gb,
+                    skip_bits(&gb,
                               sps->time_offset_length); /* time_offset */
             }
         }
@@ -126,6 +118,28 @@ static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
                h->ct_type, h->pic_struct);
     }
 
+    return 0;
+}
+
+static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
+                                 void *logctx)
+{
+    int index     = get_bits_count(gb);
+    int size_bits = get_bits_left(gb);
+    int size      = (size_bits + 7) / 8;
+
+    if (index & 7) {
+        av_log(logctx, AV_LOG_ERROR, "Unaligned SEI payload\n");
+        return AVERROR_INVALIDDATA;
+    }
+    if (size > sizeof(h->payload)) {
+        av_log(logctx, AV_LOG_ERROR, "Picture timing SEI payload too large\n");
+        return AVERROR_INVALIDDATA;
+    }
+    memcpy(h->payload, gb->buffer + index / 8, size);
+
+    h->payload_size_bits = size_bits;
+
     h->present = 1;
     return 0;
 }
@@ -436,7 +450,7 @@ int ff_h264_sei_decode(H264SEIContext *h, GetBitContext *gb,
 
         switch (type) {
         case H264_SEI_TYPE_PIC_TIMING: // Picture timing SEI
-            ret = decode_picture_timing(&h->picture_timing, &gb_payload, ps, logctx);
+            ret = decode_picture_timing(&h->picture_timing, &gb_payload, logctx);
             break;
         case H264_SEI_TYPE_USER_DATA_REGISTERED:
             ret = decode_registered_user_data(h, &gb_payload, logctx, size);

diff --git a/libavcodec/h264_sei.h b/libavcodec/h264_sei.h
index a75c3aa1753e9874817d57e1915ba9e4ce57a730..f07a5055c3159edac5c18c2a3915317b0680fcfc 100644 (file)
--- a/libavcodec/h264_sei.h
+++ b/libavcodec/h264_sei.h
@@ -20,6 +20,7 @@
 #define AVCODEC_H264_SEI_H
 
 #include "get_bits.h"
+#include "h264_ps.h"
 
 /**
  * SEI message types
@@ -79,6 +80,10 @@ typedef struct H264SEITimeCode {
 } H264SEITimeCode;
 
 typedef struct H264SEIPictureTiming {
+    // maximum size of pic_timing according to the spec should be 274 bits
+    uint8_t payload[40];
+    int     payload_size_bits;
+
     int present;
     H264_SEI_PicStructType pic_struct;
 
@@ -202,4 +207,10 @@ void ff_h264_sei_uninit(H264SEIContext *h);
  */
 const char *ff_h264_sei_stereo_mode(const H264SEIFramePacking *h);
 
+/**
+ * Parse the contents of a picture timing message given an active SPS.
+ */
+int ff_h264_sei_process_picture_timing(H264SEIPictureTiming *h, const SPS *sps,
+                                       void *logctx);
+
 #endif /* AVCODEC_H264_SEI_H */

diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index af30f6267be39cf9ec1944ec64dcc5f60f57716b..c6072738d72b434162b5f233dba5abfe8c78f7af 100644 (file)
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -1134,6 +1134,16 @@ static int h264_export_frame_props(H264Context *h)
     /* Signal interlacing information externally. */
     /* Prioritize picture timing SEI information over used
      * decoding process if it exists. */
+    if (h->sei.picture_timing.present) {
+        int ret = ff_h264_sei_process_picture_timing(&h->sei.picture_timing, sps,
+                                                     h->avctx);
+        if (ret < 0) {
+            av_log(h->avctx, AV_LOG_ERROR, "Error processing a picture timing SEI\n");
+            if (h->avctx->err_recognition & AV_EF_EXPLODE)
+                return ret;
+            h->sei.picture_timing.present = 0;
+        }
+    }
 
     if (sps->pic_struct_present_flag && h->sei.picture_timing.present) {
         H264SEIPictureTiming *pt = &h->sei.picture_timing;