[demuxers/MpegTS] Check for H.264 SPS changing midstream, stop indexi…

…ng if size change is detected
mean00 · Apr 30, 2020 · 0a7883a · 0a7883a
1 parent ab7d165
commit 0a7883a
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Showing 2 changed files with 58 additions and 1 deletion.
diff --git a/avidemux_plugins/ADM_demuxers/MpegTS/ADM_tsIndex.h b/avidemux_plugins/ADM_demuxers/MpegTS/ADM_tsIndex.h
@@ -189,10 +189,13 @@ class TsIndexerH264 : public TsIndexerBase
         uint8_t                 decodeSEI(uint32_t nalSize, uint8_t *org,uint32_t *recoveryLength,pictureStructure *nextpicstruct);
         #define                 ADM_NAL_BUFFER_SIZE (2*1024) // only used to decode SEI, should plenty enough
         uint8_t                 payloadBuffer[ADM_NAL_BUFFER_SIZE];
+        uint8_t                 spsCache[ADM_NAL_BUFFER_SIZE];
+        uint32_t                spsLen;
 public:
                 TsIndexerH264(listOfTsAudioTracks *tr) : TsIndexerBase(tr)
                 {
-                      memset(&spsInfo,0,sizeof(spsInfo));
+                    memset(&spsInfo,0,sizeof(spsInfo));
+                    spsLen=0;
                 }
                 ~TsIndexerH264()
                 {

diff --git a/avidemux_plugins/ADM_demuxers/MpegTS/ADM_tsIndexH264.cpp b/avidemux_plugins/ADM_demuxers/MpegTS/ADM_tsIndexH264.cpp
@@ -115,6 +115,10 @@ bool TsIndexerH264::findH264SPS(tsPacketLinearTracker *pkt,TSVideo &video)
             video.w=spsInfo.width;
             video.h=spsInfo.height;
             video.fps=spsInfo.fps1000;
+            spsLen=SEI_nal.payloadSize-3;
+            if(spsLen>ADM_NAL_BUFFER_SIZE)
+                spsLen=ADM_NAL_BUFFER_SIZE;
+            memcpy(spsCache,SEI_nal.payload,spsLen);
             continue;
         }
         if(startCode==NAL_SPS && sps_found) // most likely the next keyframe
@@ -347,6 +351,56 @@ uint8_t TsIndexerH264::run(const char *file, ADM_TS_TRACK *videoTrac)
                     {
                         thisUnit.consumedSoFar=pkt->getConsumed();
                     }
+                    SEI_nal.empty();
+                    uint32_t code=0xffff+0xffff0000;
+                    while(((0xffffff&code)!=1) && pkt->stillOk())
+                    {
+                        uint8_t r=pkt->readi8();
+                        code=(code<<8)+r;
+                        SEI_nal.pushByte(r);
+                    }
+                    if(!pkt->stillOk()) goto resume;
+                    uint32_t tmpLen=SEI_nal.payloadSize;
+                    aprintf("[SPS] Nal size :%d\n",tmpLen);
+                    if(tmpLen>=7 && tmpLen<=ADM_NAL_BUFFER_SIZE+3)
+                    {
+                        tmpLen-=3;
+                        bool match=!memcmp(spsCache, SEI_nal.payload, (spsLen > tmpLen)? tmpLen : spsLen);
+                        if(!match)
+                        {
+                            ADM_warning("SPS changing midstream? Checking deeper...\n");
+                            ADM_SPSInfo tmpInfo;
+                            if(extractSPSInfo(SEI_nal.payload, tmpLen, &tmpInfo))
+                            {
+                                if(spsInfo.width!=tmpInfo.width || spsInfo.height!=tmpInfo.height)
+                                {
+                                    GUI_Info_HIG(ADM_LOG_IMPORTANT, QT_TRANSLATE_NOOP("tsdemuxer","Size Change"),
+                                                 QT_TRANSLATE_NOOP("tsdemuxer","The size of the video changes at frame %u from %ux%u to %ux%u. "
+                                                                   "This is unsupported, stopping here."),
+                                                 data.nbPics, spsInfo.width, spsInfo.height, tmpInfo.width, tmpInfo.height);
+                                    result=1;
+                                    goto the_end;
+                                }
+                                match=true;
+#define MATCH(x) if(spsInfo.x != tmpInfo.x) { ADM_warning("%s value does not match.\n",#x); spsInfo.x = tmpInfo.x; match=false; }
+
+                                MATCH(CpbDpbToSkip)
+                                MATCH(hasPocInfo)
+                                MATCH(log2MaxFrameNum)
+                                MATCH(log2MaxPocLsb)
+                                MATCH(frameMbsOnlyFlag)
+                                MATCH(refFrames)
+
+                                if(!match)
+                                {
+                                    ADM_warning("Codec parameters change on the fly at frame %u, expect problems.\n",data.nbPics);
+                                    // Nevertheless, update the cached SPS
+                                    memcpy(spsCache, SEI_nal.payload, tmpLen);
+                                    spsLen=tmpLen;
+                                }
+                            }
+                        }
+                    }
                 }
                 if(!addUnit(data,unitTypeSps,thisUnit,startCodeLength))
                 {