stagefright: limit default max-input-size for AVC

AVC has a compression ratio of at least 2.  Account for this, as
some codecs refuse exorbitant max-input-size requests.

Change-Id: Ib68b485879ba33a12a486f2ce18fe100be977699
Signed-off-by: Lajos Molnar <lajos@google.com>
Bug: 11599364

1 files changed, 18 insertions, 7 deletions

diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index ad985ee..b8988e6 100644
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -1368,6 +1368,9 @@ status_t MPEG4Extractor::parseChunk(off64_t *offset, int depth) {
                 return err;
             }
 
+            const char *mime;
+            CHECK(mLastTrack->meta->findCString(kKeyMIMEType, &mime));
+
             if (max_size != 0) {
                 // Assume that a given buffer only contains at most 10 chunks,
                 // each chunk originally prefixed with a 2 byte length will
@@ -1377,19 +1380,27 @@ status_t MPEG4Extractor::parseChunk(off64_t *offset, int depth) {
             } else {
                 // No size was specified. Pick a conservatively large size.
                 int32_t width, height;
-                if (mLastTrack->meta->findInt32(kKeyWidth, &width) &&
-                        mLastTrack->meta->findInt32(kKeyHeight, &height)) {
-                    mLastTrack->meta->setInt32(kKeyMaxInputSize, width * height * 3 / 2);
-                } else {
+                if (!mLastTrack->meta->findInt32(kKeyWidth, &width) ||
+                    !mLastTrack->meta->findInt32(kKeyHeight, &height)) {
                     ALOGE("No width or height, assuming worst case 1080p");
-                    mLastTrack->meta->setInt32(kKeyMaxInputSize, 3110400);
+                    width = 1920;
+                    height = 1080;
                 }
+
+                if (!strcmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) {
+                    // AVC requires compression ratio of at least 2, and uses
+                    // macroblocks
+                    max_size = ((width + 15) / 16) * ((height + 15) / 16) * 192;
+                } else {
+                    // For all other formats there is no minimum compression
+                    // ratio. Use compression ratio of 1.
+                    max_size = width * height * 3 / 2;
+                }
+                mLastTrack->meta->setInt32(kKeyMaxInputSize, max_size);
             }
             *offset += chunk_size;
 
             // Calculate average frame rate.
-            const char *mime;
-            CHECK(mLastTrack->meta->findCString(kKeyMIMEType, &mime));
             if (!strncasecmp("video/", mime, 6)) {
                 size_t nSamples = mLastTrack->sampleTable->countSamples();
                 int64_t durationUs;