Consolidate and improve audio decoding test for all decoders.

media/filters/audio_file_reader_unittest.cc

Index: media/filters/audio_file_reader_unittest.cc
diff --git a/media/filters/audio_file_reader_unittest.cc b/media/filters/audio_file_reader_unittest.cc
index 28c9837cb2e189d48629c3f0d5fec9adca0af999..fbf7f53e981bf29f1ee084476f9d8e7d1e1b6028 100644
--- a/media/filters/audio_file_reader_unittest.cc
+++ b/media/filters/audio_file_reader_unittest.cc
@@ -3,12 +3,14 @@
 // found in the LICENSE file.
 
 #include "base/logging.h"
+#include "base/md5.h"
 #include "base/memory/scoped_ptr.h"
 #include "build/build_config.h"
 #include "media/base/audio_bus.h"
 #include "media/base/audio_hash.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/test_data_util.h"
+#include "media/ffmpeg/ffmpeg_common.h"
 #include "media/filters/audio_file_reader.h"
 #include "media/filters/in_memory_url_protocol.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -40,6 +42,37 @@ class AudioFileReaderTest : public testing::Test {
     EXPECT_EQ(expected_audio_hash, audio_hash.ToString());
   }
 
+  // Verify packets are consistent across demuxer runs.
+  void VerifyPackets() {
+    const int kReads = 3;
+    const int kTestPasses = 2;
+
+    // Seek to the effective start of the file.  For ogg files this may not be
+    // the actual first packet, but it should correspond to the first decoded

[wolenetz, 2014/06/06 21:00:05]

If not the actual first packet, why not? (elaborate in comment, please)

[DaleCurtis, 2014/06/06 21:17:00]

I think this is sufficient.  I don't need to explain the details of why ogg in a
pita here :)

+    // samples.
+    ASSERT_TRUE(reader_->SeekForTesting(base::TimeDelta()));

[wolenetz, 2014/06/06 21:00:05]

nit: is base::TimeDelta() the first timestamp in all the test data? Perhaps I'm
confused about av_seek_frame(), but if 0 isn't the lowest/first pts, then would
seek fail?

[DaleCurtis, 2014/06/06 21:17:00]

Setting AV_SEEK_FLAG_BACKWARD chooses the first PTS <= 0

[wolenetz, 2014/06/06 21:52:31]

Ok. I was confusing with MSE where lowest PTS in a media segment after an init
segment can be > 0.

+
+    AVPacket packet;
+    std::vector<std::string> packet_md5_hashes_;
+    for (int i = 0; i < kTestPasses; ++i) {
+      for (int j = 0; j < kReads; ++j) {
+        ASSERT_TRUE(reader_->ReadPacketForTesting(&packet));
+        const std::string md5_hash = base::MD5String(base::StringPiece(
+            reinterpret_cast<char*>(packet.data), packet.size));
+
+        // On the first pass save the MD5 hash of each packet, on subsequent
+        // passes ensure it matches.
+        if (i == 0)
+          packet_md5_hashes_.push_back(md5_hash);
+        else
+          EXPECT_EQ(packet_md5_hashes_[j], md5_hash);
+
+        av_free_packet(&packet);
+      }
+      ASSERT_TRUE(reader_->SeekForTesting(base::TimeDelta()));
+    }
+  }
+
   void RunTest(const char* fn, const char* hash, int channels, int sample_rate,
                base::TimeDelta duration, int frames, int trimmed_frames) {
     Initialize(fn);
@@ -50,6 +83,9 @@ class AudioFileReaderTest : public testing::Test {
               reader_->GetDuration().InMicroseconds());
     EXPECT_EQ(frames, reader_->GetNumberOfFrames());
     ReadAndVerify(hash, trimmed_frames);
+
+    // After the normal checks, perform some seek based tests on the packets.
+    VerifyPackets();
   }
 
   void RunTestFailingDemux(const char* fn) {