For most check_bitstream() functions this just avoids having
to dereference s->streams[pkt->stream_index] themselves; but for
meta-muxers it will allow to forward the packet to stream with
a different stream_index (belonging to a different AVFormatContext)
without using a spare packet.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It avoids branches lateron and will allow to easily avoid the overhead
of the linked list currently in use in case there is only one stream.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The documentation of said packet ("Every user has to ensure that
this packet is blank after using it") perfectly fits how we use said
packet in the generic muxing code. Better than the documentation of pkt.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Currently the interleave_packet functions use a packet for
a new packet to be interleaved (may be NULL if there is none) and
a packet for output; said packet is always a stack packet in
interleaved_write_packet(). But all the interleave_packet functions
in use first move the packet to the packet list and then check whether
a packet can be returned, i.e. the effective lifetime of the new packet
ends before the packet for output is touched.
So one can use one packet both for input and output by adding a new
parameter that indicates whether there is a packet to add to the packet
list; there is just one complication: In case the muxer is flushed,
there is no packet available. This can be solved by reusing one of
the packets from AVFormatInternal. They are currently unused when
flushing in av_interleaved_write_frame().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The BSF API treats such packets as signalling EOF and therefore
such a packet might corrupt the BSF state. In such a case,
the guarantee that av_interleaved_write_frame() always frees
the packet is not upheld.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Do this by allocating AVStream together with the data that is
currently in AVStreamInternal; or rather: Put AVStream at the
beginning of a new structure called FFStream (which encompasses
more than just the internal fields and is a proper context in its own
right, hence the name) and remove AVStreamInternal altogether.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This gets rid of ugly "->internal" and is in preparation for removing
AVStreamInternal altogether.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Do this by allocating AVFormatContext together with the data that is
currently in AVFormatInternal; or rather: Put AVFormatContext at the
beginning of a new structure called FFFormatContext (which encompasses
more than just the internal fields and is a proper context in its own
right, hence the name) and remove AVFormatInternal altogether.
The biggest simplifications occured in avformat_alloc_context(), where
one can now simply call avformat_free_context() in case of errors.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This gets rid of ugly "->internal" and is in preparation for removing
AVFormatInternal altogether.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Up until now, ff_write_chained() copied the packet (manually, not with
av_packet_move_ref()) from a packet given to it to a stack packet whose
timing and stream_index is then modified before being sent to another
muxer via av_(interleaved_)write_frame(). Afterwards it is intended to
sync the fields of the packet relevant to freeing again; yet this only
encompasses buf, side_data and side_data_elems and not the newly added
opaque_ref. The other fields are not synced so that the returned packet
can have a size > 0 and data != NULL despite its buf being NULL (this
always happens in the interleaved codepath; before commit
fe251f77c8 it could also happen in the
noninterleaved one). This leads to double-frees if the interleaved
codepath is used and opaque_ref is set.
This commit therefore changes this by directly reusing the packet
instead of a spare packet. Given that av_write_frame() does not
change the packet given to it, one only needs to restore the timing
information to return it as it was; for the interleaved codepath
it is not possible to do likewise*, because av_interleaved_write_frame()
takes ownership of the packets given to it and returns blank packets.
But precisely because of this users of the interleaved codepath
have no legitimate expectation that their packet will be returned
unchanged. In line with av_interleaved_write_frame() ff_write_chained()
therefore returns blank packets when using the interleaved codepath.
Making the only user of said codepath compatible with this was trivial.
*: Unless one wanted to create a full new reference.
Reviewed-by: Lynne <dev@lynne.ee>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
An AVStream's internal AVCodecContext is pretty much unused for muxing:
The only place where any of its fields are set is
avformat_transfer_internal_stream_timing_info() where its time base is
set based upon the desired output format. The max_b_frames field is
never set at all, so don't read it in mux.c.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The next pointer is kept at the end for backwards compatability until the
major bump, when it should ideally be moved at the front.
Signed-off-by: James Almer <jamrial@gmail.com>
And make it const, so the caller doesn't attempt to change it.
ff_get_muxer_ts_offset() should be used to get the muxer timestamp offset.
Signed-off-by: James Almer <jamrial@gmail.com>
Factor out the code into a separate muxing-specific function.
Stop accessing the deprecated AVStream-embedded codec context, use the
average framerate (if specified) instead.
Those are private fields, no reason to have them exposed in a public
header. Since there are some (semi-)public fields located after these,
even though this section is supposed to be private, keep some dummy
padding there until the next major bump to preserve ABI compatibility.
Since commit c5324d92c5 all custom
interleave_packet() functions always return clean packets (even on
error), so that unreferencing manually can be removed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Call it directly from write_packets_common() instead of indirectly
through prepare_input_packet().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit stops using pkt->stream_index as index in an AVFormatContext's
streams array before actually comparing the value with the count of
streams in said array. 96e5e6abb9 used
pkt->stream_index in prepare_input_packet() before checking and
6406351222 did likewise in
write_packets_common().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Previously only 1:1 bitstream filters were supported, the end of the stream was
not signalled to the bitstream filters and time base changes were ignored.
This change also allows muxers to set up bitstream filters regardless of the
autobsf flag during write_header instead of during check_bitstream and those
bitstream filters will always be executed.
Signed-off-by: Marton Balint <cus@passwd.hu>
Current muxers only use a single bitstream filter, so there is no need to
maintain code which operates on a list of bitstream filters. When multiple
bitstream filters are needed muxers can simply use a list bitstream filter.
If there is a use case in the future when different bitstream filters should be
added at subsequent packets then a new API possibly involving reconfiguring the
list bitstream filter can be added knowing the exact requirements.
Signed-off-by: Marton Balint <cus@passwd.hu>
mux.c was split from utils.c in 55f9037f38
and during this split all headers were simply copied without checking if
they were only needed in the part that stayed in utils.c (or whether
these haeders were needed at all). As a result quite a lot of headers
in mux.c are unnecessary. This commit removes them.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
When no packet could be output, the interleavement functions
nevertheless initialized the packet destined for output (with the
exception of the data and size fields, making the initialization
pointless), although it will not be used at all. So remove the
initializations.
Reviewed-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
write_packet() currently saves the original timestamps of the packet it
got and restores them in case writing fails. This is unnecessary as we
are no longer working directly with the user-supplied AVPacket here; and
it is also pointless because the timestamps may already have been
altered before write_packet().
So remove this and add a general comment to the function that timestamps
may be modified; also remove a long outdated comment about side data.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
The documentation of av_write_frame() explicitly states that the function
doesn't take ownership of the packets sent to it; while av_write_frame()
does not directly unreference the packets after having written them, it
nevertheless modifies the packet in various ways:
1. The timestamps might be modified either by prepare_input_packet() or
compute_muxer_pkt_fields().
2. If a bitstream filter gets applied, it takes ownership of the
reference and the side-data in the packet sent to it.
In case of do_packet_auto_bsf(), the end result is that the returned packet
contains the output of the last bsf in the chain. If an error happens,
a blank packet will be returned; a packet may also simply not lead to
any output (vp9_superframe).
This also implies that side data needs to be really copied and can't be
shared with the input packet.
The method choosen here minimizes copying of data: When the input isn't
refcounted and no bitstream filter is applied, the packet's data will
not be copied.
Notice that packets that contain uncoded frames are exempt from this
because these packets are not owned by and returned to the user. This
also moves unreferencing the packets containing uncoded frames to
av_write_frame() in the noninterleaved codepath; in the interleaved
codepath, these packets are already freed in av_interleaved_write_frame(),
so that unreferencing the packets in write_uncoded_frame_internal() is
no longer needed. It has been removed.
Reviewed-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Now that ff_interleave_add_packet() always returns blank packets, the
input packet to ff_interleave_packet_per_dts() will always be blank on
return as well (if supplied) and the same goes for interleave_packet()
in mux.c. Document these facts and remove the redundant resetting that
happened in av_interleaved_write_frame().
The last reference to the (long removed) destruct field that AVPackets
once had has been removed as well when updating the documentation of
ff_interleave_packet_per_dts().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
When an error happened in ff_interleave_add_packet() when adding
a packet to the packet queue, said packet would not be unreferenced
in ff_interleave_add_packet(), but would be zeroed in
av_interleaved_write_frame(), which results in a memleak.
This has been fixed: ff_interleave_add_packet() now always unreferences
the input packet on error; as a result, it always returns blank packets
which has been documented. Relying on this a call to av_packet_unref()
in ff_audio_rechunk_interleave() can be removed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
If writing uncoded frames in noninterleaved mode fails at the preparatory
steps (i.e. before it reaches write_packet()), the packet would not be
unreferenced and the frame would leak. This is fixed by unreferencing
the packet in write_uncoded_frame_internal() instead.
This also makes it possible to remove the unreferencing in
write_packet() itself: In noninterleaved mode frames are now freed in
write_uncoded_frame_internal(), while they are freed in interleaved
mode when their containing packet gets unreferenced (like normal
packets).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Currently uncoded frames (i.e. packets whose data actually points to an
AVFrame) are not refcounted. As a consequence, calling av_packet_unref()
on them will not free them, but may simply make sure that they leak by
losing the pointer to the frame.
This commit changes this by actually making uncoded frames refcounted.
In order not to rely on sizeof(AVFrame) (which is not part of the public
API and so must not be used here in libavformat) the packet's data is
changed to a (padded) buffer containing just a pointer to an AVFrame.
Said buffer is owned by an AVBuffer with a custom free function that
frees the frame as well as the buffer. Thereby the pointer/the AVBuffer
owns the AVFrame.
Said ownership can actually be transferred by copying and resetting
the pointer, as might happen when actually writing the uncoded frames
in AVOutputFormat.write_uncoded_frame() (although currently no muxer
makes use of this possibility).
This makes packets containing uncoded frames compatible with
av_packet_unref(). This already has three advantages in interleaved mode:
1. If an error happens at the preparatory steps (before the packet is
put into the interleavement queue), the frame is properly freed.
2. If the trailer is never written, the frames still in the
interleavement queue will now be properly freed by
ff_packet_list_free().
3. The custom code for moving the packet to the packet list in
ff_interleave_add_packet() can be removed.
It will also simplify fixing further memleaks in future commits.
Suggested-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
It is unnecessary to call prepare_input_packet if there is no packet as
it doesn't do anything, except when the currently inactive code guarded
by !FF_API_COMPUTE_PKT_FIELDS2 || !FF_API_LAVF_AVCTX becomes active:
Then attempting to access pkt->stream_index will crash.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
