This function returns the encoded data of a frame, one slice at a time
directly when that slice is encoded, instead of waiting for the full
frame to be done. However this field has a debatable usefulness, since
it looks like it is just a convoluted way to get data at lowest
possible latency, or a somewhat hacky way to store h263 in RFC-2190
rtp encapsulation.
Moreover when multi-threading is enabled (which is by default) the order
of returned slices is not deterministic at all, making the use of this
function not reliable at all (or at the very least, more complicated
than it should be).
So, for the reasons stated above, and being used by only a single encoder
family (mpegvideo), this field is deemed unnecessary, overcomplicated,
and not really belonging to libavcodec. Libavformat features a complete
implementation of RFC-2190, for any other case.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Currently, multiple slices with just one thread produce corrupted
output.
Additionally, enable slice structured mode for h263(+)
Bug-Id: 912
CC: libav-stabl@libav.org
When the encoder is fed with less frames than its delay, the picture list
looks like { NULL, NULL, ..., frame, frame, frame }. When flushing the
encoder (input frame == NULL), we need to ensure the picture list is
shifted enough so that we do not return an empty packet, which would
mean the encoder has finished, while it has not encoded any frame.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
When the encoder is fed with less frames than its delay, the picture list looks like { NULL, NULL, ..., frame, frame, frame }. When flushing the encoder (input frame == NULL), we need to ensure the picture list is shifted enough so that we do not return an empty packet, which would mean the encoder has finished, while it has not encoded any frame.
Before the patch, the command:
'./ffmpeg_g -loglevel debug -f lavfi -i "testsrc=d=0.01" -bf 2 -vcodec mpeg2video out.mxf' prints:
Output stream #0:0 (video): 1 frames encoded; 0 packets muxed (0 bytes);
After:
Output stream #0:0 (video): 1 frames encoded; 1 packets muxed (8058 bytes);
Relates to ticket #4817.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This should fix the first undefined behavior reported in:
https://trac.ffmpeg.org/ticket/4727.
I can't reproduce the runtime behavior reported in the ticket, hence I
can't confirm that this actually fixes the exact issue reported in the
ticket.
Regardless, I can confirm that this is a genuine issue, and that
negative shifts can (and do) occur, fixed by this.
Tested with FATE.
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
These field are difficult to interpret, and are provided by a single
encoder (mpegvideoenc). In general they do not belong to a structure
containing raw data only, so remove them from AVFrame.
Mpegvideoenc now uses a private field in Picture for its internal
computations.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Reduces the number of times the vbv retry code is used and should have no
effect on quality
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This option is extremely codec specific and only a few codecs employ it.
Move it to codec private options instead: mpegenc family supports only 3
values, xavs and x264 use 5, and xvid has a different metric entirely.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This parameter can be used to inform the allocation code about how much
downsizing might occur, and can be used to optimize how to allocate the
packet
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The stats are a superset of the quality factor, also allowing the picture type and encoder "PSNR" stats to be exported
This also replaces the native by fixed little endian order for the affected side data
AV_PKT_DATA_QUALITY_FACTOR is left as a synonym of AV_PKT_DATA_QUALITY_STATS
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The rationale is that coded_frame was only used to communicate key_frame,
pict_type and quality to the caller, as well as a few other random fields,
in a non predictable, let alone consistent way.
There was agreement that there was no use case for coded_frame, as it is
a full-sized AVFrame container used for just 2-3 int-sized properties,
which shouldn't even belong into the AVCodecContext in the first place.
The appropriate AVPacket flag can be used instead of key_frame, while
quality is exported with the new AVPacketSideData quality factor.
There is no replacement for the other fields as they were unreliable,
mishandled or just not used at all.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
This is necessary to preserve the quality information currently exported
with coded_frame. Add the new side data to every encoder that needs it,
and use it in avconv.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Allocating coded_frame is what most encoders do anyway, so it makes
sense to always allocate and free it in a single place. Moreover a lot
of encoders freed the frame with av_freep() instead of the correct API
av_frame_free().
This bring uniformity to encoder behaviour and prevents applications
from erroneusly accessing this field when not allocated. Additionally
this helps isolating encoders that export information with coded_frame,
and heavily simplifies its deprecation.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
They are used by dnxhd and mpegvideo_enc exclusively, move them to codec
private options instead.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Having this macro in an header only facilitates the use of such header.
The code increase is minimal and files have one less dependency
on mpegvideo.h.
The main ff_alloc_picture() function is made more generic with all the
parameters necessary as arguments. This will allows to move most of the
related functions to a separate file later.
Right now wrappers are provided to try and minimize the number of
changes in the code.
Vittorio Giovara
Anton Khirnov
Luca Barbato
Alexis Ballier
Michael Niedermayer
Christophe Gisquet
Ganesh Ajjanagadde
Michael Niedermayer