Originally, AVFormatContext and a metadata dict were provided to ff_vorbis_comment(),
but this presented issues if an AVStream was being updated or the metadata on
AVFormatContext wasn't actually being updated. To remedy this, ff_vorbis_stream_comment()
explicitly updates a stream's metadata and sets any necessary flags.

ff_vorbis_comment() does not modify any flags, and any calls to it that update
AVFormatContext's metadata (just a single call) must also update
AVFormatContext.event_flags after detecting any metadata changes to the provided
dictionary, as signaled by a positive return value.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

It is commonly stored in a vorbiscomment block in codec private data.

Setting seek_preroll value in AVCodecContext for Opus streams
embedded in ogg container.
Signed-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fix timestamp calculation for code 3 Ogg Opus packets with less than
2 bytes in the last segment (e.g. packet length 255 or 256).
A sample that would seek incorrectly in ffplay can be created with:
  ffmpeg -i in.wav -b:a 34k -vbr off -frame_duration 60 out.opus
and libopus 1.1

Also do not read past the end of the buffer when a packet has length 0.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Regression since 39d11d59

os->pduration would be wrongly assigned a negative value on invalid packets
instead of aborting.
Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

based on code from oggparsevorbis
Fixes Ticket3124
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Opus Pre Skip is exported in AVCodecContext->delay similar to how
it is done for matroska. Doing the same for ogg too.
Signed-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: James Almer <jamrial@gmail.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Line comes from ecab1c77
and was not merged previously

Thanks-to: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Re-wording a log message that's no longer true and changing its
severity level to debug.

Signed-off by: Vignesh Venkatasubramanian <vigneshv@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Adding support for end trimming Opus embedded in Ogg container.

Signed-Off By: Vignesh Venkatasubramanian <vigneshv@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This patch also introduces CODEC_ID_OPUS.