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Autres articles (37)
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Vous pouvez bien entendu ajouter le votre grâce au formulaire en bas de page. -
Use, discuss, criticize
13 avril 2011, parTalk to people directly involved in MediaSPIP’s development, or to people around you who could use MediaSPIP to share, enhance or develop their creative projects.
The bigger the community, the more MediaSPIP’s potential will be explored and the faster the software will evolve.
A discussion list is available for all exchanges between users. -
Supporting all media types
13 avril 2011, parUnlike most software and media-sharing platforms, MediaSPIP aims to manage as many different media types as possible. The following are just a few examples from an ever-expanding list of supported formats : images : png, gif, jpg, bmp and more audio : MP3, Ogg, Wav and more video : AVI, MP4, OGV, mpg, mov, wmv and more text, code and other data : OpenOffice, Microsoft Office (Word, PowerPoint, Excel), web (html, CSS), LaTeX, Google Earth and (...)
Sur d’autres sites (6089)
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ffmpeg stream chrome kiosk mode ubuntu 16.04 server
15 février 2021, par RaulI have a weird out-of-sync issue while using ffmpeg to stream to youtube live a chrome browser from an ub untu 16.04 server.



Issue : output video streamed to youtube has audio/video out of sync, sometimes with as much as 3s



Current flow :



1) start pulseaudio - we using something like this to start it :



pulseaudio --start -vvv --disallow-exit --log-target=syslog --high-priority --exit-idle-time=-1 --daemonize



2) start Xvfb



Xvfb :0 -ac -screen 0 1920x1080x24



3) start chrome linux in kiosk mode



google-chrome --kiosk --disable-gpu --incognito --no-first-run --disable-java --disable-plugins --disable-translate --disk-cache-size=$((1024 * 1024)) --disk-cache-dir=/tmp/chrome/ --user-data-dir=/tmp/chrome/ --force-device-scale-factor=1 --window-size=1920,1080 --window-position=0,0 LOCATION_URL



4) start ffmpeg



ffmpeg -y \
 -thread_queue_size 8192 -rtbufsize 250M -f x11grab -video_size 1920x1080 -framerate 24 -i :0 \
 -thread_queue_size 8192 -channel_layout stereo -f alsa -i pulse \
 -c:v libx264 -pix_fmt yuv420p -c:v libx264 -g 48 -crf 24 -filter:v fps=24 -preset ultrafast -tune zerolatency \
 -c:a aac -strict -2 -channel_layout stereo -ab 96k -ac 2 -flags +global_header \
 -f flv YOUTUBE_LIVE_STREAMING_RTMP



Note : this is running on an amazon ec2 instance, meaning there is no soundcard, so alsa and pulseaudio are creating a dummy audio card. However, the latency does not come from there. Logs :



Nov 25 06:14:22 ip-172-31-29-8 pulseaudio[26602]: [pulseaudio] protocol-native.c: Adjust latency mode enabled, configuring sink latency to half of overall latency.
Nov 25 06:14:22 ip-172-31-29-8 pulseaudio[26602]: [pulseaudio] protocol-native.c: Requested latency=23.22 ms, Received latency=23.22 ms
Nov 25 06:14:22 ip-172-31-29-8 pulseaudio[26602]: [pulseaudio] protocol-native.c: Final latency 69.66 ms = 23.22 ms + 2*11.61 ms + 23.22 ms



At this point, here's what we observed :



- 

-
if we start ffmpeg exactly after issuing the command to start chrome, we see the DTS errors from ffmpeg. Audio is out of sync with the video and has delay of 3-5seconds AHEAD. We also noticed the out of sync remains the same for the full duration of the stream
-
if we start ffmpeg after around 10seconds, audio and video are almost in sync. We then manually added a -itsoffset -0.125 to the ffmpeg command and everything is perfect.







Questions :



- 

- Why would ffmpeg have so much lag if it's started right after chrome ?
- Is starting the ffmpeg after 10s or X seconds the expected behavior ? That is, is this because the system needs to wait for audio/video signals to be "ready" or something ?
- Is there a way to 100% calculate or know when Chrome is fully ready and start ffmpeg ? We found sometimes it takes 5s, sometimes 10. Depends on the URL we load.
- Besides the DTS error that ffmpeg throws, is there any other way to know if audio/video is out-of-sync ? as sometimes we have a delay of between 0.5 to 1s, but ffmpeg does not report anything. And a restart is required to "re-balance" the audio/video inputs and get them back in sync.
- Can pulseaudio be the problem in this scenario ?













Thank you



UPDATE Dec 20



We were able to do some tricks to force chrome to start the audio on page load, and that will force connect to pulseaudio. Doing that, plus adding a 3s delay for ffmpeg to start, there is no more delay when ffmpeg starts.
However, our app is a webRTC app, and we have a STRANGER thing happening : if we start the page with no webcam/audio, once the webcam/audio is enabled, ffmpeg (while showing no errors) has a delay of 2s or so. While keep talking, in about max 30s, that delay is GONE.



So the new questions are :



- 

- Besides the DTS error that ffmpeg throws, is there any other way to know if audio/video is out-of-sync ? as sometimes we have a delay of between 0.5 to 1s, but ffmpeg does not report anything.
- What could cause the initial audio/video out of sync issue and then catching up ?






-
-
FFMPEG compiled binaries don't run using MinGW
9 juin 2015, par Paul KnopfI am trying to build windows executables/dlls for Windows XP, and they are not working. They are the correct architecture. They run fine on my Windows 8 device machine.
I used dependency walker to find missing DLLs, and all were present.
Here are the compiled executables I am trying to run.
I ran the windows build script for ffmpeg.
Here is a
dumpbin /headers ffmpeg.exeMicrosoft (R) COFF/PE Dumper Version 10.00.30319.01
Copyright (C) Microsoft Corporation. All rights reserved.
Dump of file ffmpeg.exe
PE signature found
File Type: EXECUTABLE IMAGE
FILE HEADER VALUES
14C machine (x86)
7 number of sections
51A40 time date stamp Sun Jan 04 15:53:20 1970
0 file pointer to symbol table
0 number of symbols
E0 size of optional header
32F characteristics
Relocations stripped
Executable
Line numbers stripped
Symbols stripped
Application can handle large (>2GB) addresses
32 bit word machine
Debug information stripped
OPTIONAL HEADER VALUES
10B magic # (PE32)
2.25 linker version
41400 size of code
4FA00 size of initialized data
1200 size of uninitialized data
14E0 entry point (004014E0)
1000 base of code
43000 base of data
400000 image base (00400000 to 00456FFF)
1000 section alignment
200 file alignment
4.00 operating system version
1.00 image version
4.00 subsystem version
0 Win32 version
57000 size of image
400 size of headers
597A9 checksum
3 subsystem (Windows CUI)
140 DLL characteristics
Dynamic base
NX compatible
200000 size of stack reserve
1000 size of stack commit
100000 size of heap reserve
1000 size of heap commit
0 loader flags
10 number of directories
0 [ 0] RVA [size] of Export Directory
51000 [ 36F0] RVA [size] of Import Directory
0 [ 0] RVA [size] of Resource Directory
0 [ 0] RVA [size] of Exception Directory
0 [ 0] RVA [size] of Certificates Directory
0 [ 0] RVA [size] of Base Relocation Directory
0 [ 0] RVA [size] of Debug Directory
0 [ 0] RVA [size] of Architecture Directory
0 [ 0] RVA [size] of Global Pointer Directory
56004 [ 18] RVA [size] of Thread Storage Directory
0 [ 0] RVA [size] of Load Configuration Directory
0 [ 0] RVA [size] of Bound Import Directory
517F0 [ 6C4] RVA [size] of Import Address Table Directory
0 [ 0] RVA [size] of Delay Import Directory
0 [ 0] RVA [size] of COM Descriptor Directory
0 [ 0] RVA [size] of Reserved Directory
SECTION HEADER #1
.text name
412BC virtual size
1000 virtual address (00401000 to 004422BB)
41400 size of raw data
400 file pointer to raw data (00000400 to 000417FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
60500060 flags
Code
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Execute Read
SECTION HEADER #2
.data name
19C virtual size
43000 virtual address (00443000 to 0044319B)
200 size of raw data
41800 file pointer to raw data (00041800 to 000419FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0700040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #3
.rdata name
A7D8 virtual size
44000 virtual address (00444000 to 0044E7D7)
A800 size of raw data
41A00 file pointer to raw data (00041A00 to 0004C1FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
40700040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Only
SECTION HEADER #4
.bss name
1200 virtual size
4F000 virtual address (0044F000 to 004501FF)
0 size of raw data
0 file pointer to raw data
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0700080 flags
Uninitialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #5
.idata name
36F0 virtual size
51000 virtual address (00451000 to 004546EF)
3800 size of raw data
4C200 file pointer to raw data (0004C200 to 0004F9FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0300040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #6
.CRT name
3C virtual size
55000 virtual address (00455000 to 0045503B)
200 size of raw data
4FA00 file pointer to raw data (0004FA00 to 0004FBFF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0300040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #7
.tls name
20 virtual size
56000 virtual address (00456000 to 0045601F)
200 size of raw data
4FC00 file pointer to raw data (0004FC00 to 0004FDFF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0300040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
Summary
1000 .CRT
2000 .bss
1000 .data
4000 .idata
B000 .rdata
42000 .text
1000 .tlsWhen I attempt to run the executable on XP, it just closes. There is no "missing dll" messages, nor anything in the event viewer.
-
FFMPEG compiled binaries don't run on XP using MinGW
10 juin 2015, par Paul KnopfI am trying to build windows executables/dlls for Windows XP, and they are not working. They are the correct architecture. They run fine on my Windows 8 device machine.
I used dependency walker to find missing DLLs, and all were present.
Here are the compiled executables I am trying to run.
I ran the windows build script for ffmpeg.
Here is a
dumpbin /headers ffmpeg.exeMicrosoft (R) COFF/PE Dumper Version 10.00.30319.01
Copyright (C) Microsoft Corporation. All rights reserved.
Dump of file ffmpeg.exe
PE signature found
File Type: EXECUTABLE IMAGE
FILE HEADER VALUES
14C machine (x86)
7 number of sections
51A40 time date stamp Sun Jan 04 15:53:20 1970
0 file pointer to symbol table
0 number of symbols
E0 size of optional header
32F characteristics
Relocations stripped
Executable
Line numbers stripped
Symbols stripped
Application can handle large (>2GB) addresses
32 bit word machine
Debug information stripped
OPTIONAL HEADER VALUES
10B magic # (PE32)
2.25 linker version
41400 size of code
4FA00 size of initialized data
1200 size of uninitialized data
14E0 entry point (004014E0)
1000 base of code
43000 base of data
400000 image base (00400000 to 00456FFF)
1000 section alignment
200 file alignment
4.00 operating system version
1.00 image version
4.00 subsystem version
0 Win32 version
57000 size of image
400 size of headers
597A9 checksum
3 subsystem (Windows CUI)
140 DLL characteristics
Dynamic base
NX compatible
200000 size of stack reserve
1000 size of stack commit
100000 size of heap reserve
1000 size of heap commit
0 loader flags
10 number of directories
0 [ 0] RVA [size] of Export Directory
51000 [ 36F0] RVA [size] of Import Directory
0 [ 0] RVA [size] of Resource Directory
0 [ 0] RVA [size] of Exception Directory
0 [ 0] RVA [size] of Certificates Directory
0 [ 0] RVA [size] of Base Relocation Directory
0 [ 0] RVA [size] of Debug Directory
0 [ 0] RVA [size] of Architecture Directory
0 [ 0] RVA [size] of Global Pointer Directory
56004 [ 18] RVA [size] of Thread Storage Directory
0 [ 0] RVA [size] of Load Configuration Directory
0 [ 0] RVA [size] of Bound Import Directory
517F0 [ 6C4] RVA [size] of Import Address Table Directory
0 [ 0] RVA [size] of Delay Import Directory
0 [ 0] RVA [size] of COM Descriptor Directory
0 [ 0] RVA [size] of Reserved Directory
SECTION HEADER #1
.text name
412BC virtual size
1000 virtual address (00401000 to 004422BB)
41400 size of raw data
400 file pointer to raw data (00000400 to 000417FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
60500060 flags
Code
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Execute Read
SECTION HEADER #2
.data name
19C virtual size
43000 virtual address (00443000 to 0044319B)
200 size of raw data
41800 file pointer to raw data (00041800 to 000419FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0700040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #3
.rdata name
A7D8 virtual size
44000 virtual address (00444000 to 0044E7D7)
A800 size of raw data
41A00 file pointer to raw data (00041A00 to 0004C1FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
40700040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Only
SECTION HEADER #4
.bss name
1200 virtual size
4F000 virtual address (0044F000 to 004501FF)
0 size of raw data
0 file pointer to raw data
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0700080 flags
Uninitialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #5
.idata name
36F0 virtual size
51000 virtual address (00451000 to 004546EF)
3800 size of raw data
4C200 file pointer to raw data (0004C200 to 0004F9FF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0300040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #6
.CRT name
3C virtual size
55000 virtual address (00455000 to 0045503B)
200 size of raw data
4FA00 file pointer to raw data (0004FA00 to 0004FBFF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0300040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
SECTION HEADER #7
.tls name
20 virtual size
56000 virtual address (00456000 to 0045601F)
200 size of raw data
4FC00 file pointer to raw data (0004FC00 to 0004FDFF)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0300040 flags
Initialized Data
RESERVED - UNKNOWN
RESERVED - UNKNOWN
Read Write
Summary
1000 .CRT
2000 .bss
1000 .data
4000 .idata
B000 .rdata
42000 .text
1000 .tlsWhen I attempt to run the executable on XP, it just closes. There is no "missing dll" messages, nor anything in the event viewer.
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