Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.
In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.
There are multiple important problems with this approach:
- the fields in AVCodecContext are in general one of
* stream parameters
* codec options
* codec state
However, it's not clear which ones are which. It is consequently
unclear which fields are a demuxer allowed to set or a muxer allowed to
read. This leads to erratic behaviour depending on whether decoding or
encoding is being performed or not (and whether it uses the AVStream
embedded codec context).
- various synchronization issues arising from the fact that the same
context is used by several different APIs (muxers/demuxers,
parsers, bitstream filters and encoders/decoders) simultaneously, with
there being no clear rules for who can modify what and the different
processes being typically delayed with respect to each other.
- avformat_find_stream_info() making it necessary to support opening
and closing a single codec context multiple times, thus
complicating the semantics of freeing various allocated objects in the
codec context.
Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
The packetizer only supports splitting at GOB headers - if
such aren't available frequently enough, it splits at any
random byte offset (not at a macroblock boundary either, which
would be allowed by the spec) and sends a payload header pretend
that it starts with a GOB header.
As long as a receiver doesn't try to handle such cases cleverly
but just drops broken frames, this shouldn't matter too much
in practice.
Signed-off-by: Martin Storsjö <martin@martin.st>
* commit 'e5cfc8fdad901c9487fe896421972852f38bcf5':
sdp: Provide out of bound parameter sets for HEVC if extradata is set
Merged-by: Michael Niedermayer <michaelni@gmx.at>
By using ff_avc_write_annexb_extradata instead of the h264_mp4toannexb
BSF, the code for doing the conversion itself is kept much shorter,
there's less state to restore at the end, we don't risk leaving the
AVCodecContext in an inconsistent state if returning early due to
errors, etc.
Also add a missing free if the base64 encoding fails.
Signed-off-by: Martin Storsjö <martin@martin.st>
This avoids a memory leak (or having to worry about freeing the
config string) if the colorspace isn't accepted.
Signed-off-by: Martin Storsjö <martin@martin.st>
* commit '094a7405e5d8463d7d167d893e04934ec1a84ecd':
x86: ABSB: port to cpuflags
sdp: Include SRTP crypto params if using the srtp protocol
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
bgmc: Fix av_malloc checks in ff_bgmc_init()
rtp: set the payload type as stream id
Conflicts:
libavformat/rtpenc_chain.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Optional sdp speex payload parameter is outputed only when
data is encoded. It's not printed in case of stream copy.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
mingw/cygwin: Stop adding -fno-common to gcc CFLAGS
Restructure av_log_missing_feature message
rtp: Support packetization/depacketization of opus
file: Set the return value type for lseek to int64_t.
ppc: fix Altivec build with old compilers
build: add LTO support for PGI compiler
build: add -Mdse to PGI optimisation flags
rtpenc_vp8: Update the packetizer to the latest spec version
rtpdec_vp8: Make the depacketizer implement the latest spec draft
doc: allow building with old texi2html versions
avutil: skip old_pix_fmts.h since it is just a list
Conflicts:
libavcodec/aacdec.c
libavcodec/h264.c
libavcodec/ppc/fmtconvert_altivec.c
libavcodec/utils.c
libavformat/file.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
nutdec: const correctness for get_v_trace/get_s_trace function arguments
truemotion2: Request samples for old TM2 headers
rtpdec: Remove a useless ff_ prefix from a static symbol
rtpdec: Support depacketizing speex
rtpenc: Add support for packetizing speex
Conflicts:
libavformat/rtpdec.c
libavformat/sdp.c
libavformat/version.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This packetization scheme simply places the full packets into the
RTP packet without any extra header bytes.
Signed-off-by: Martin Storsjö <martin@martin.st>
* qatar/master:
rtp: Packetization of JPEG (RFC 2435)
smoothstreamingenc: Copy the SAR on the AVStreams as well
Conflicts:
Changelog
libavformat/rtpenc.c
libavformat/version.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* libspeex audio codec is no longer considered unsupported
when using rtp as output format.
* SDP rtpmap is added for speex payload, formatted according to RFC
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
