Moved codec-specific audio packet splitting into decoders.

webrtc/modules/audio_coding/codecs/ilbc/ilbc_unittest.cc

Index: webrtc/modules/audio_coding/codecs/ilbc/ilbc_unittest.cc
diff --git a/webrtc/modules/audio_coding/codecs/ilbc/ilbc_unittest.cc b/webrtc/modules/audio_coding/codecs/ilbc/ilbc_unittest.cc
index c23cbc44e808a60185b30a6ad93d18778fdbe160..4a27f4cb98658d77dc55ba578b31473efdae37ea 100644
--- a/webrtc/modules/audio_coding/codecs/ilbc/ilbc_unittest.cc
+++ b/webrtc/modules/audio_coding/codecs/ilbc/ilbc_unittest.cc
@@ -54,4 +54,80 @@ TEST(IlbcTest, BadPacket) {
                            decoded_samples.data(), &speech_type));
 }
 
+class SplitIlbcTest : public ::testing::TestWithParam<std::pair<int, int> > {
+ protected:
+  virtual void SetUp() {
+    const std::pair<int, int> parameters = GetParam();
+    num_frames_ = parameters.first;
+    frame_length_ms_ = parameters.second;
+    frame_length_bytes_ = (frame_length_ms_ == 20) ? 38 : 50;
+  }
+  size_t num_frames_;
+  int frame_length_ms_;
+  size_t frame_length_bytes_;
+};
+
+// Test splitting sample-based payloads.

[hlundin-webrtc, 2016/09/09 12:52:52]

iLBC does not split sample-based.

[ossu, 2016/09/12 11:26:37]

Nope! The comment is an old one but it's still wrong. I'll fix!

+TEST_P(SplitIlbcTest, NumFrames) {
+  AudioDecoderIlbc decoder;
+  const size_t frame_length_samples = frame_length_ms_ * 8;
+  size_t payload_length_bytes = frame_length_bytes_ * num_frames_;

[kwiberg-webrtc, 2016/09/12 02:11:01]

const?

[ossu, 2016/09/12 11:26:37]

Acknowledged.

+  rtc::Buffer payload(payload_length_bytes);
+  // Fill payload with increasing integers {0, 1, 2, ...}.
+  for (size_t i = 0; i < payload.size(); ++i) {
+    payload[i] = static_cast<uint8_t>(i);
+  }
+
+  auto splits = decoder.SplitPacket(payload);
+  EXPECT_EQ(num_frames_, splits.size());
+
+  size_t frame_num = 0;
+  uint8_t payload_value = 0;
+  for (const auto& split : splits) {
+    EXPECT_EQ(frame_length_samples * frame_num, split.timestamp_offset);
+    EXPECT_EQ(frame_length_bytes_, split.num_bytes);
+    for (size_t i = 0; i < split.num_bytes; ++i, ++payload_value) {
+      EXPECT_EQ(payload_value, payload[split.byte_offset + i]);
+    }
+    ++frame_num;
+  }
+}
+
+// Test 1 through 5 frames of 20 and 30 ms size.
+// Also test the maximum number of frames in one packet for 20 and 30 ms.
+// The maximum is defined by the largest payload length that can be uniquely
+// resolved to a frame size of either 38 bytes (20 ms) or 50 bytes (30 ms).
+INSTANTIATE_TEST_CASE_P(
+    PayloadSplitter, SplitIlbcTest,
+    ::testing::Values(std::pair<int, int>(1, 20),  // 1 frame, 20 ms.
+                      std::pair<int, int>(2, 20),  // 2 frames, 20 ms.
+                      std::pair<int, int>(3, 20),  // And so on.
+                      std::pair<int, int>(4, 20),
+                      std::pair<int, int>(5, 20),
+                      std::pair<int, int>(24, 20),
+                      std::pair<int, int>(1, 30),
+                      std::pair<int, int>(2, 30),
+                      std::pair<int, int>(3, 30),
+                      std::pair<int, int>(4, 30),
+                      std::pair<int, int>(5, 30),
+                      std::pair<int, int>(18, 30)));
+
+// Test too large payload size.
+TEST(IlbcPayloadSplitter, TooLargePayload) {
+  AudioDecoderIlbc decoder;
+  size_t kPayloadLengthBytes = 950;

[kwiberg-webrtc, 2016/09/12 02:11:01]

constexpr

[ossu, 2016/09/12 11:26:37]

Acknowledged.

+  rtc::Buffer payload(kPayloadLengthBytes);

[kwiberg-webrtc, 2016/09/12 02:11:01]

const

[ossu, 2016/09/12 11:26:37]

Acknowledged.

+  auto splits = decoder.SplitPacket(payload);

[kwiberg-webrtc, 2016/09/12 02:11:01]

const

[ossu, 2016/09/12 11:26:37]

Acknowledged.

+  EXPECT_TRUE(splits.empty());
+}
+
+// Payload not an integer number of frames.
+TEST(IlbcPayloadSplitter, UnevenPayload) {
+  AudioDecoderIlbc decoder;
+  size_t kPayloadLengthBytes = 39;  // Not an even number of frames.
+  rtc::Buffer payload(kPayloadLengthBytes);
+  auto splits = decoder.SplitPacket(payload);

[kwiberg-webrtc, 2016/09/12 02:11:01]

constexpr, const, const

[ossu, 2016/09/12 11:26:37]

Acknowledged.

+  EXPECT_TRUE(splits.empty());
+}
+
 }  // namespace webrtc