Commit Graph

4 Commits

Author SHA1 Message Date
KongQun Yang 40ea1286b9 Add support for EditLists in ISO-BMFF
- EditLists in input files are parsed and applied to sample timestamps.
- An EditList will be inserted in the ISO-BMFF output if
  - There is an offset between the initial presentation timestamp (pts)
    and decoding timestamp (dts). Chrome, as of M67, still uses dts in
    buffered range API [1], which creates various problems when buffered
    range by pts does not align with buffered range by dts. There is
    another bug in Chrome that applies EditList to pts only [2]. This
    means that we can insert an EditList to align pts range and dts range.
  - MediaSamples have negative timestamps (e.g. for Audio Priming).

You may notice the below change on some contents:
- Some media duration is reduced by one or two frames. This is because
  EditList in the input file was ignored in the previous code, so video
  streams start with a zero dts and a non-zero pts; the smaller of dts
  and pts was used as the starting timestamp (related to the earlier
  workaround for Chrome's dts bug), so the calculated duration was
  actually a bit larger than the actual duration. Now with EditList
  applied, the initial pts is reduced to zero, so the media duration is
  also reduced to reflect the actual and correct media duration.

It may also result in negative timestamps in TS/HLS Packed Audio, which
will be addressed in a follow up CL.

Fixes #112.
Partially address b/110782437.

[1] https://crbug.com/718641, fixed but behind MseBufferByPts.
[2] https://crbug.com/354518. Chrome is planning to enable the fix for
    [1] before addressing this bug, so we are safe.

Change-Id: I59317740ad3807ca66fa74b3a18fdf7f32c96aeb
2018-07-26 23:20:21 +00:00
KongQun Yang f68b4252b8 Sync protobuf to v3.3.0
disable-clang-format

Change-Id: I520178aa9bb8fd8a00a7009279bf30d7cdb8d5a8
2018-05-10 23:07:59 +00:00
KongQun Yang b2932d5a33 Fix bitrate for DASH on-demand profile too
Removed the logic in MuxerListener to estimate bandwidth from file
size and duration, since it is not compliant to the spec.

MpdBuilder will estimate bandwidth from segment size and duration
if bandwidth is not specified in MediaInfo.

Here is the statement from DASH spec (23009-1:2014):

Consider a hypothetical constant bitrate channel of
bandwidth with the value of this attribute in bits per second
(bps). Then, if the Representation is continuously delivered
at this bitrate, starting at any SAP that is indicated either by
@startwithsap or by any Segment Index box, a client can
be assured of having enough data for continuous playout
providing playout begins after @minbuffertime *
@bandwidth bits have been received (i.e. at time
@minbuffertime after the first bit is received).
For dependent Representations this value specifies the
bandwidth according to the above definition for the
aggregation of this Representation and all complementary
Representations.

Fixes #376.

Change-Id: I0fddce39e709d0cded0a4c9ae59adbbcc97ec5ea
2018-04-24 23:25:02 +00:00
Aaron Vaage fb2dfe129c Update CheckTestResults to sanitize media info
Change MediaInfo media paths in test output to only use the filename so
that they can be compared between test runs.

Change-Id: I26bb3f5ce79a83400b8a162c61cf5b54e41f9c70
2018-03-13 16:37:10 +00:00