H264 bitstream parser.

webrtc/base/bitbuffer.cc

Index: webrtc/base/bitbuffer.cc
diff --git a/webrtc/base/bitbuffer.cc b/webrtc/base/bitbuffer.cc
index cd3661343b290ae25aed1e34a04a7390643c5ead..bbd1047f901df16974e3d0322713f814a8cda0dc 100644
--- a/webrtc/base/bitbuffer.cc
+++ b/webrtc/base/bitbuffer.cc
@@ -187,6 +187,17 @@ bool BitBuffer::ReadExponentialGolomb(uint32_t* val) {
   return true;
 }
 
+bool BitBuffer::ReadSignedExponentialGolomb(int32_t* val) {
+  // TODO(pbos): Is there a corner case I'm missing here?
+  uint32_t unsigned_val;
+  if (!ReadExponentialGolomb(&unsigned_val))

[noahric, 2015/09/03 17:48:58]

Brackets to match the rest of the file :-p

[pbos-webrtc, 2015/09/04 10:01:20]

Done.

+    return false;
+  if ((unsigned_val & 1) == 0)

[noahric, 2015/09/03 17:48:58]

This if just falls through and overwrites val, so that can't work correctly.
if/else?

Also it'd be helpful to have a short comment explaining what the sequence is,
e.g.
// Signed exponential golomb values are just the unsigned values
// mapped to the sequence 0, 1, -1, 2, -2, etc. in order.

(plus a unit test, for at least a small set of expected values)

[pbos-webrtc, 2015/09/04 10:01:20]

Done, which also uncovered additional bugs. That are now fixed. Thanks. :')

+    *val = (unsigned_val + 1) / 2;
+  *val = -(unsigned_val / 2);
+  return true;
+}
+
 void BitBuffer::GetCurrentOffset(
     size_t* out_byte_offset, size_t* out_bit_offset) {
   CHECK(out_byte_offset != NULL);