[FFmpeg-trac] #10177(undetermined:new): FFMPEG Demuxer-Muxer unable to operate with all input information: -r and -copy_unknown not working
FFmpeg
trac at avcodec.org
Tue Feb 7 19:48:17 EET 2023
#10177: FFMPEG Demuxer-Muxer unable to operate with all input information: -r and
-copy_unknown not working
-------------------------------------+-------------------------------------
Reporter: Javier | Type: defect
Delgado del Cerro |
Status: new | Priority: normal
Component: | Version: 5.0.2
undetermined |
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
I am using FFMPEG as a demuxer-muxer to receive a MPEG source with audio
and video streams, separate the streams and introduce the least possible
delay. I have all the information about the input, including the
container, codecs, audio and video rate, and audio channels.
I've been researching the different options that FFMPEG provides, and I've
found the following ones which could help me:
- `-codec:a` and `-codec:v` to provide the information about the input's
audio and video codecs.
- `-f` to provide the information about the used container.
- `-r:v` to provide the information about the video framerate. (I've also
tried with `-framerate`, but it seems that is only supported by a few
demuxers, and mpeg is not one of them).
- `-probesize` to avoid spending time probing the input, as I can provide
the inpromation.
- `-copy_unknown` to simply copy the streams instead of failing if it
can't be recognized.
With all this, I'm using the following command:
`./ffmpeg -hide_banner -loglevel debug -codec:v h264 -codec:a pcm_alaw
-flags low_delay -probesize 32 -analyzeduration 0 -r:v 15 -f mpeg -i
udp://127.0.0.1:41071?listen -y -map 0:a:0? -acodec copy -copy_unknown -ar
8000 -payload_type 8 -f rtp udp://127.0.0.1:33605?pkt_size=1200 -map
0:v:0? -vcodec copy -copy_unknown -payload_type 96 -f rtp
udp://127.0.0.1:48527?pkt_size=1200`
Which outputs:
{{{
Splitting the commandline.
Reading option '-hide_banner' ... matched as option 'hide_banner' (do not
show program banner) with argument '1'.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging
level) with argument 'debug'.
Reading option '-codec:v' ... matched as option 'codec' (codec name) with
argument 'h264'.
Reading option '-codec:a' ... matched as option 'codec' (codec name) with
argument 'pcm_alaw'.
Reading option '-flags' ... matched as AVOption 'flags' with argument
'low_delay'.
Reading option '-probesize' ... matched as AVOption 'probesize' with
argument '32'.
Reading option '-analyzeduration' ... matched as AVOption
'analyzeduration' with argument '0'.
Reading option '-r:v' ... matched as option 'r' (set frame rate (Hz value,
fraction or abbreviation)) with argument '15'.
Reading option '-f' ... matched as option 'f' (force format) with argument
'mpeg'.
Reading option '-i' ... matched as input url with argument
'udp://127.0.0.1:41071?listen'.
Reading option '-y' ... matched as option 'y' (overwrite output files)
with argument '1'.
Reading option '-map' ... matched as option 'map' (set input stream
mapping) with argument '0:a:0?'.
Reading option '-acodec' ... matched as option 'acodec' (force audio codec
('copy' to copy stream)) with argument 'copy'.
Reading option '-copy_unknown' ... matched as option 'copy_unknown' (Copy
unknown stream types) with argument '1'.
Reading option '-ar' ... matched as option 'ar' (set audio sampling rate
(in Hz)) with argument '8000'.
Reading option '-payload_type' ... matched as AVOption 'payload_type' with
argument '8'.
Reading option '-f' ... matched as option 'f' (force format) with argument
'rtp'.
Reading option 'udp://127.0.0.1:33605?pkt_size=1200' ... matched as output
url.
Reading option '-map' ... matched as option 'map' (set input stream
mapping) with argument '0:v:0?'.
Reading option '-vcodec' ... matched as option 'vcodec' (force video codec
('copy' to copy stream)) with argument 'copy'.
Reading option '-copy_unknown' ... matched as option 'copy_unknown' (Copy
unknown stream types) with argument '1'.
Reading option '-payload_type' ... matched as AVOption 'payload_type' with
argument '96'.
Reading option '-f' ... matched as option 'f' (force format) with argument
'rtp'.
Reading option 'udp://127.0.0.1:48527?pkt_size=1200' ... matched as output
url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option hide_banner (do not show program banner) with argument 1.
Applying option loglevel (set logging level) with argument debug.
Applying option y (overwrite output files) with argument 1.
Applying option copy_unknown (Copy unknown stream types) with argument 1.
Last message repeated 1 times
Successfully parsed a group of options.
Parsing a group of options: input url udp://127.0.0.1:41071?listen.
Applying option codec:v (codec name) with argument h264.
Applying option codec:a (codec name) with argument pcm_alaw.
Applying option r:v (set frame rate (Hz value, fraction or abbreviation))
with argument 15.
Applying option f (force format) with argument mpeg.
Successfully parsed a group of options.
Opening an input file: udp://127.0.0.1:41071?listen.
[mpeg @ 0x55a769cc3d40] Opening 'udp://127.0.0.1:41071?listen' for reading
[udp @ 0x55a769cc4b00] No default whitelist set
[udp @ 0x55a769cc4b00] end receive buffer size reported is 425984
[mpeg @ 0x55a769cc3d40] Before avformat_find_stream_info() pos: 6 bytes
read:40 seeks:0 nb_streams:0
[mpeg @ 0x55a769cc3d40] probing stream 1 pp:2500
[mpeg @ 0x55a769cc3d40] probed stream 1
[mpeg @ 0x55a769cc3d40] parser not found for codec pcm_alaw, packets or
times may be invalid.
[mpeg @ 0x55a769cc3d40] Probe buffer size limit of 32 bytes reached
[mpeg @ 0x55a769cc3d40] Stream #0: not enough frames to estimate rate;
consider increasing probesize
[mpeg @ 0x55a769cc3d40] Could not find codec parameters for stream 0
(Video: h264, 1 reference frame, none): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and
'probesize' (32) options
[mpeg @ 0x55a769cc3d40] After avformat_find_stream_info() pos: 87804 bytes
read:88476 seeks:0 frames:1
Input #0, mpeg, from 'udp://127.0.0.1:41071?listen':
Duration: N/A, start: 50436.772978, bitrate: 64 kb/s
Stream #0:0[0x1e0], 0, 1/90000: Video: h264, 1 reference frame, none,
90k tbr, 90k tbn
Stream #0:1[0x1c0], 1, 1/90000: Audio: pcm_alaw, 8000 Hz, mono, s16, 64
kb/s
Successfully opened the file.
Parsing a group of options: output url
udp://127.0.0.1:33605?pkt_size=1200.
Applying option map (set input stream mapping) with argument 0:a:0?.
Applying option acodec (force audio codec ('copy' to copy stream)) with
argument copy.
Applying option ar (set audio sampling rate (in Hz)) with argument 8000.
Applying option f (force format) with argument rtp.
Successfully parsed a group of options.
Opening an output file: udp://127.0.0.1:33605?pkt_size=1200.
[udp @ 0x55a769cf6500] No default whitelist set
Successfully opened the file.
Parsing a group of options: output url
udp://127.0.0.1:48527?pkt_size=1200.
Applying option map (set input stream mapping) with argument 0:v:0?.
Applying option vcodec (force video codec ('copy' to copy stream)) with
argument copy.
Applying option f (force format) with argument rtp.
Successfully parsed a group of options.
Opening an output file: udp://127.0.0.1:48527?pkt_size=1200.
[udp @ 0x55a769d08fc0] No default whitelist set
Successfully opened the file.
Output #0, rtp, to 'udp://127.0.0.1:33605?pkt_size=1200':
Metadata:
encoder : Lavf59.16.100
Stream #0:0, 0, 1/8000: Audio: pcm_alaw, 8000 Hz, mono, s16, 64 kb/s
[rtp @ 0x55a769d06f40] dimensions not set
Could not write header for output file #1 (incorrect codec parameters ?):
Invalid argument
Error initializing output stream 1:0 --
Stream mapping:
Stream #0:1 -> #0:0 (copy)
Stream #0:0 -> #1:0 (copy)
Last message repeated 1 times
[AVIOContext @ 0x55a769d06d40] Statistics: 0 bytes written, 0 seeks, 0
writeouts
[AVIOContext @ 0x55a769d19800] Statistics: 0 bytes written, 0 seeks, 0
writeouts
[AVIOContext @ 0x55a769cd4fc0] Statistics: 88476 bytes read, 0 seeks
}}}
Expected behavior:
FFMPEG should be able to operate with all input information and avoid
using a large probesize, resulting in the least possible latency. FFMPEG
should not crush, as the `-copy_unknown` option is specified (I've also
tried specifying it on the input, but the result is the same)
Actual behavior:
FFMPEG is unable to operate without specifying a large probesize, leading
to increased latency and in some cases, failure. The `-copy_unknown` and
`-re:v 15` options are ignored.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/10177>
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