Commit Graph

4 Commits

Author SHA1 Message Date
koln67 5b9fd409a5
[MP4] Change major brand from isom to mp41
This fixes warnings that 'isom' can only be a compatible instead of major brand.

Issue #755.
2020-09-08 15:45:21 -07:00
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 772aa7c93f Do not force earliest_presentation_time to 0 for VOD
Instead, the actual earliest presentation time is used except for
the first segment if there is an offset between presentation time
(pts) and decoding time (dts).

Chrome (as of v66) reports dts instead of pts in buffered ranges in
MSE API. To avoid breaking Chrome, the earliest_presentation_time
of the first segment is set to its dts as Chrome does not like negative
values for
  adjusted dts = dts + Period@start (0 for the first period)
                 - presentationTimeOffset (earliest_presentation_time).

Fixes #303.

Change-Id: I5ca80e05d5570961400499436f2bcc01f06e69e0
2018-04-09 18:39:15 +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