RCWT (Raw Captions With Time) is a format native to ccextractor,
a commonly used OSS tool for processing 608/708 Closed Captions (CC).
RCWT can be used to archive the original extracted CC bitstream.
The muxer was added in January 2024. In this commit, add the demuxer.
One can now demux RCWT files for rendering in ccaption_dec or interop
with ccextractor (which produces RCWT). Using the muxer/demuxer combo,
the CC bits can be kept for processing or rendering with either tool.
This can be an effective way to backup an original CC stream, including
format extensions like EIA-708 and overall original presentation.
Signed-off-by: Marth64 <marth64@proxyid.net>
The wav demuxer by default tried to demux 4096-byte packets which caused
packets with very few number of samples for files with high channel count.
This caused a significant overhead especially since the latest ffmpeg.c
threading changes.
So let's use a similar approach for selecting audio frame size which is already
used in the PCM demuxer, which is to read 25 times per second but at most 1024
samples.
Signed-off-by: Marton Balint <cus@passwd.hu>
For badly interleaved files, interleave packets from multiple tracks
at the demuxer level can trigger seeking back and forth, which can be
dramatically slow depending on the protocol. Demuxer level interleave
can be useless sometimes, e.g., reading mp4 via http and then
transcoding/remux to DASH. Disable this option when you don't need the
demuxer level interleave, and want to avoid the IO penalizes.
Co-authored-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
Current HLS implementation simply skip a failed segment to catch up
the stream, but this is not optimal for some use cases like livestream
recording.
Add an option to retry a failed segment to ensure the output file is
a complete stream.
Signed-off-by: gnattu <gnattuoc@me.com>
Reviewed-by: Steven Liu <liuqi05@kuaishou.com>
VP6 alpha in EA format is a second VP6 encoded video stream where only the Y
component is used and is interpreted as the alpha channel of the first VP6
stream. The alpha VP6 stream is muxed separately from the main VP6 stream, has
its own stream headers and packet headers. In theory the two streams might not
even have the same resolution (although most likely that is not something that
is seen or supported in the wild), but the format is capable of doing it.
Merged VP6 alpha (also known as the VP6A codec) means that a packet of the
video stream contains the corresponding packet of both VP6 substreams like
this:
{OffsetOfAlpha, DataPacket, AlphaDataPacket}
So data and alpha data of a frame is merged to a single packet, this is how VP6
video with alpha is muxed in FLV and SWF.
The first approach is more like how the demuxer sees data in the EA format,
unfortunately it is different to what the FLV or SWF format expects, so -
having no better place for it in the framework - I decided to do an optional
format conversion in the EA demuxer.
Signed-off-by: Marton Balint <cus@passwd.hu>
Very high stts sample deltas may occasionally be intended but usually
they are written in error or used to store a negative value for dts correction
when treated as signed 32-bit integers.
This option lets the user set an upper limit, beyond which the delta is clamped to 1.
Values greater than the limit if negative when cast to int32 are used to adjust onward dts.
Unit is the track time scale. Default is UINT_MAX - 48000*10 which
allows upto a 10 second dts correction for 48 kHz audio streams while
accommodating 99.9% of uint32 range.
Signed-off-by: Gyan Doshi <ffmpeg@gyani.pro>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
libavformat/img2.h: New field export_path_metadata to
VideoDemuxData to only allow the use of the extra metadata
upon explicit user request, for security reasons.
libavformat/img2dec.c: Modify image2 demuxer to make available
two special metadata entries called lavf.image2dec.source_path
and lavf.image2dec.source_basename, which represents, respectively,
the complete path to the source image for the current frame and
the basename i.e. the file name related to the current frame.
These can then be used by filters like drawtext and others. The
metadata fields will only be available when explicitly enabled
with image2 option -export_path_metadata 1.
doc/demuxers.texi: Documented the new metadata fields available
for image2 and how to use them.
doc/filters.texi: Added an example on how to use the new metadata
fields with drawtext filter, in order to plot the input file path
to each output frame.
Usage example:
ffmpeg -f image2 -export_path_metadata 1 -pattern_type glob
-framerate 18 -i '/path/to/input/files/*.jpg'
-filter_complex drawtext="fontsize=40:fontcolor=white:
fontfile=FreeSans.ttf:borderw=2:bordercolor=black:
text='%{metadata\:lavf.image2dec.source_basename\:NA}':x=5:y=50"
output.avi
Fixes#2874.
Signed-off-by: Alexandre Heitor Schmidt <alexandre.schmidt@gmail.com>
Signed-off-by: Marton Balint <cus@passwd.hu>
Add http_seekable option for HTTP partial requests, when The
EXT-X-BYTERANGE tag indicates that a Media Segment is a sub-range
of the resource identified by its URI, we can use HTTP partial
requests to get the Media Segment.
Reviewed-by: Steven Liu <lq@chinaffmpeg.org>
Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
Cleanup the applehttp as demuxer name, when use the command :
ffmpeg -formats, get the confused information like:
"
E hls Apple HTTP Live Streaming
D hls,applehttp Apple HTTP Live Streaming
"
we don't use applehttp as the demuxer/muxer name usually, so
cleanup the applehttp and update the documents.
After the change, get the information from "ffmpeg -formats":
"
DE hls Apple HTTP Live Streaming
"
Reviewed-by: Steven Liu <lq@onvideo.cn>
Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
This new optional flag makes it easier to deal with mpegts
samples where the PMT is updated and elementary streams move
to different PIDs in the middle of playback.
Previously, new AVStreams were created per PID, and it was up
to the user to figure out which streams had migrated to a new PID
(by iterating over the list of AVProgram and making guesses), and
switch seamlessly to the new AVStream during playback.
Transcoding or remuxing these streams with ffmpeg on the CLI was
also quite painful, and the user would need to extract each set
of PIDs into a separate file and then stitch them back together.
With this new option, the mpegts demuxer will automatically detect
PMT changes and feed data from the new PID to the original AVStream
that was created for the orignal PID. For mpegts samples with
stream_identifier_descriptor available, the unique ID is used to
merge PIDs together. If the stream id is not available, the demuxer
attempts to map PIDs based on their position within the PMT.
With this change, I am able to playback and transcode/remux these
two samples which previously caused issues:
https://tmm1.s3.amazonaws.com/pmt-version-change.tshttps://kuroko.fushizen.eu/videos/pid_switch_sample.ts
I also have another longer sample in which the PMT changes
repeatedly and ES streams move to different pids three times
during playback:
https://tmm1.s3.amazonaws.com/multiple-pmt-change.ts
Demuxing this sample with the new option shows several new log
messages as the PMT changes are handled:
[mpegts] detected PMT change (program=1, version=3/6, pcr_pid=0xf98/0xfb7)
[mpegts] re-using existing video stream 0 (pid=0xf98) for new pid=0xfb7
[mpegts] re-using existing audio stream 1 (pid=0xf99) for new pid=0xfb8
[mpegts] re-using existing audio stream 2 (pid=0xf9a) for new pid=0xfb9
[mpegts] detected PMT change (program=1, version=6/3, pcr_pid=0xfb7/0xf98)
[mpegts] detected PMT change (program=1, version=3/4, pcr_pid=0xf98/0xf9b)
[mpegts] re-using existing video stream 0 (pid=0xf98) for new pid=0xf9b
[mpegts] re-using existing audio stream 1 (pid=0xf99) for new pid=0xf9c
[mpegts] re-using existing audio stream 2 (pid=0xf9a) for new pid=0xf9d
[mpegts] detected PMT change (program=1, version=4/5, pcr_pid=0xf9b/0xfa9)
[mpegts] re-using existing video stream 0 (pid=0xf98) for new pid=0xfa9
[mpegts] re-using existing audio stream 1 (pid=0xf99) for new pid=0xfaa
[mpegts] re-using existing audio stream 2 (pid=0xf9a) for new pid=0xfab
[mpegts] detected PMT change (program=1, version=5/6, pcr_pid=0xfa9/0xfb7)
Signed-off-by: Aman Gupta <aman@tmm1.net>
Some filtered mpegts streams may erroneously include PMTs for
programs that are not advertised in the PAT. This confuses ffmpeg
and most players because multiple audio/video streams are created
and it is unclear which ones actually contain data.
See for example https://tmm1.s3.amazonaws.com/unknown-pmts.ts
In this sample, the PAT advertises exactly one program. But the
pid it points to for the program's PMT contains PMTs for other
programs as well. This is because the broadcaster decided to
re-use the same pid for multiple program PMTs.
The hardware that filtered the original multi-program stream
into a single-program stream did so by rewriting the PAT to
contain only the program that was requested. But since it just
passed through the PMT pid referenced in the PAT, multiple PMTs
are still present for the other programs.
Before:
Input #0, mpegts, from 'unknown-pmts.ts':
Duration: 00:00:10.11, start: 80741.189700, bitrate: 9655 kb/s
Program 4
Stream #0:2[0x41]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], Closed Captions, 11063 kb/s, 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
Stream #0:3[0x44](eng): Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), fltp, 384 kb/s
Stream #0:4[0x45](spa): Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 128 kb/s
No Program
Stream #0:0[0x31]: Video: mpeg2video ([2][0][0][0] / 0x0002), none(tv), 90k tbr, 90k tbn, 90k tbc
Stream #0:1[0x34](eng): Audio: ac3 (AC-3 / 0x332D4341), 0 channels, fltp
Stream #0:5[0x51]: Video: mpeg2video ([2][0][0][0] / 0x0002), none, 90k tbr, 90k tbn
Stream #0:6[0x54](eng): Audio: ac3 (AC-3 / 0x332D4341), 0 channels
With skip_unknown_pmt=1:
Input #0, mpegts, from 'unknown-pmts.ts':
Duration: 00:00:10.11, start: 80741.189700, bitrate: 9655 kb/s
Program 4
Stream #0:0[0x41]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], Closed Captions, 11063 kb/s, 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
Stream #0:1[0x44](eng): Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), fltp, 384 kb/s
Stream #0:2[0x45](spa): Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 128 kb/s
Signed-off-by: Aman Gupta <aman@tmm1.net>
Some http/1.0 implementations, like python's SimpleHTTPServer, can only support one client connection at a time. Making a second request while the first is still connected leads to a deadlock.
This change enables multiple connections for http/1.1 servers only, which need to support keepalive by default and should have no problem with concurrent requests.
Signed-off-by: Aman Gupta <aman@tmm1.net>
This improves network throughput of the hls demuxer by avoiding
the latency introduced by downloading segments one at a time.
The problem is particularly noticable over high-latency network
connections: for instance, if RTT is 250ms, there will a 250ms idle
period between when one segment response is read and the next one
starts.
The obvious solution to this is to use HTTP pipelining, where a
second request can be sent (on the persistent http/1.1 connection)
before the first response is fully read. Unfortunately the way the
http protocol is implemented in avformat makes implementing pipleining
very complex.
Instead, this commit simulates pipelining using two separate persistent
http connections. This has the advantage of working independently of
the http_persistent option, and can be used with http/1.0 servers as
well. The pair of connections is swapped every time a new segment starts
downloading, and a request for the next segment is sent on the secondary
connection right away. This means the second response will be ready and
waiting by the time the current response is fully read.
Signed-off-by: Aman Gupta <aman@tmm1.net>
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
This teaches the HLS demuxer to use the HTTP protocols
multiple_requests=1 option, to take advantage of "Connection:
Keep-Alive" when downloading playlists and segments from the HLS server.
With the new option, you can avoid TCP connection and TLS negotiation
overhead, which is particularly beneficial when streaming via a
high-latency internet connection.
Similar to the http_persistent option recently implemented in hlsenc.c
Signed-off-by: Aman Gupta <aman@tmm1.net>
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Fixes: loop.m3u
The default max iteration count of 1000 is arbitrary and ideas for a better solution are welcome
Found-by: Xiaohei and Wangchu from Alibaba Security Team
Previous version reviewed-by: Steven Liu <lingjiujianke@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
