merge from libav: 585dc1aece
If the metadata packet is corrupted, flv_read_metabody can accidentally
read past the start of the next packet. If the start of the next packet
had been flushed out of the IO buffer, we would be unable to seek to
the right position (on a nonseekable stream).
Prefer to clearly error out instead of silently trying to read from a
desynced stream which will only be interpreted as garbage.
merge from libav: 585dc1aece
If the metadata packet is corrupted, flv_read_metabody can accidentally
read past the start of the next packet. If the start of the next packet
had been flushed out of the IO buffer, we would be unable to seek to
the right position (on a nonseekable stream).
Prefer to clearly error out instead of silently trying to read from a
desynced stream which will only be interpreted as garbage.
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>
refer to SPEC:
Annex E. The FLV File Format said:
E.3 TheFLVFileBody have a table:
Field Type Comment
PreviousTagSize0 UI32 Always 0
Reviewed-by: Bela Bodecs <bodecsb@vivanet.hu>
Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>
Ever since the codecpar changes, this has been always printed when
opening a flv file. This is because the codecpar changes made all
streams to be added lazily as read_packet is called.
Otherwise the codec context and codecpar might disagree on the codec id,
triggering asserts in av_parser_parse2.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
when parsing keyframe index metadata, list the message by trace log
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Current code doesn't initialize AVPacket::pos. Made it point to FLVTAG so flv_read_packet can decode from pos
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
It is supposed to be a flag. The only currently defined value is
AVIO_SEEKABLE_NORMAL, but other ones may be added in the future.
However all the current lavf code treats this field as a bool (mainly
for historical reasons).
Change all those cases to properly check for AVIO_SEEKABLE_NORMAL.
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.
Some muxer use the FLV field PreviousTagSize to be the sum of tag
length. Without this change, the flv demuxer think the file is broken
and the re-sync will fail.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
For http, this avoids spurious warnings about failed requests (e.g.
HTTP error 416 Requested Range Not Satisfiable), if the last packet
is truncated and the size read is bogus.
Signed-off-by: Martin Storsjö <martin@martin.st>
When loading a truncated flv file, it would previously try to do a seek to
the end of every packet read. For some input protocols (such as http), such
repeated seek attempts are cripple the reading performance.
Signed-off-by: Martin Storsjö <martin@martin.st>
The current muxer behaviour is to create streams in read_header() based
on the audio/video presence flags, but fill in the stream parameters
later when we actually get some packets for them. This is rather shady,
since other demuxers set the stream parameters immediately when the
stream is created and do not touch the stream codec context after that.
Change the flv demuxer to behave in the same way as other similar
demuxers -- create the streams only when we get a packet for them.
This error was produced by rtmproto.c, it is possibly such streams
where dumped, this commit is needed to support them
Fixes: z0e.flv
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
In case of resync, always free the packet, but retry only if the resync
did not get to the end of the file. Otherwise, there is a memory leak when the
last packet in the file is corrupted.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
