Expand support for fragmented mp4

Don't require that there are no other boxes between mdat and moof boxes, or
that moof immediately follows moov.
Fix SAP parsing and seeking to exact start of segment.

Change-Id: I668644c5c7866dd2512f3b7f745fba438ae6e627

1 files changed, 27 insertions, 12 deletions

diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index 81ed6f7..f80772a 100644
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -488,12 +488,12 @@ status_t MPEG4Extractor::readMetaData() {
             break;
         }
         uint32_t chunk_type = ntohl(hdr[1]);
-        if (chunk_type == FOURCC('s', 'i', 'd', 'x')) {
-            // parse the sidx box too
-            continue;
-        } else if (chunk_type == FOURCC('m', 'o', 'o', 'f')) {
+        if (chunk_type == FOURCC('m', 'o', 'o', 'f')) {
             // store the offset of the first segment
             mMoofOffset = offset;
+        } else if (chunk_type != FOURCC('m', 'd', 'a', 't')) {
+            // keep parsing until we get to the data
+            continue;
         }
         break;
     }
@@ -1921,9 +1921,10 @@ status_t MPEG4Extractor::parseSegmentIndex(off64_t offset, size_t size) {
             ALOGW("sub-sidx boxes not supported yet");
         }
         bool sap = d3 & 0x80000000;
-        bool saptype = d3 >> 28;
-        if (!sap || saptype > 2) {
-            ALOGW("not a stream access point, or unsupported type");
+        uint32_t saptype = (d3 >> 28) & 7;
+        if (!sap || (saptype != 1 && saptype != 2)) {
+            // type 1 and 2 are sync samples
+            ALOGW("not a stream access point, or unsupported type: %08x", d3);
         }
         total_duration += d2;
         offset += 12;
@@ -2899,9 +2900,20 @@ status_t MPEG4Source::parseChunk(off64_t *offset) {
                 }
             }
             if (chunk_type == FOURCC('m', 'o', 'o', 'f')) {
-                // *offset points to the mdat box following this moof
-                parseChunk(offset); // doesn't actually parse it, just updates offset
-                mNextMoofOffset = *offset;
+                // *offset points to the box following this moof. Find the next moof from there.
+
+                while (true) {
+                    if (mDataSource->readAt(*offset, hdr, 8) < 8) {
+                        return ERROR_END_OF_STREAM;
+                    }
+                    chunk_size = ntohl(hdr[0]);
+                    chunk_type = ntohl(hdr[1]);
+                    if (chunk_type == FOURCC('m', 'o', 'o', 'f')) {
+                        mNextMoofOffset = *offset;
+                        break;
+                    }
+                    *offset += chunk_size;
+                }
             }
             break;
         }
@@ -3706,7 +3718,7 @@ status_t MPEG4Source::fragmentedRead(
                 const SidxEntry *se = &mSegments[i];
                 if (totalTime + se->mDurationUs > seekTimeUs) {
                     // The requested time is somewhere in this segment
-                    if ((mode == ReadOptions::SEEK_NEXT_SYNC) ||
+                    if ((mode == ReadOptions::SEEK_NEXT_SYNC && seekTimeUs > totalTime) ||
                         (mode == ReadOptions::SEEK_CLOSEST_SYNC &&
                         (seekTimeUs - totalTime) > (totalTime + se->mDurationUs - seekTimeUs))) {
                         // requested next sync, or closest sync and it was closer to the end of
@@ -3751,7 +3763,10 @@ status_t MPEG4Source::fragmentedRead(
         newBuffer = true;
 
         if (mCurrentSampleIndex >= mCurrentSamples.size()) {
-            // move to next fragment
+            // move to next fragment if there is one
+            if (mNextMoofOffset <= mCurrentMoofOffset) {
+                return ERROR_END_OF_STREAM;
+            }
             off64_t nextMoof = mNextMoofOffset;
             mCurrentMoofOffset = nextMoof;
             mCurrentSamples.clear();