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La conservation du net art au musée. Les stratégies à l’œuvre
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Sur d’autres sites (9629)
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Shaka Player returns 4001 error - Node.js local web server playing MPEG-DASH
27 mai 2020, par salgarjiI've used Chrome inspection tool to access 'Console' and analyze what is happening. Complete error information :



D {severity: 2, category: 4, code: 4001, data: Array(1), handled: false}
category: 4
code: 4001
data: Array(1)
0: "http://localhost:8080/dash_segmentos/video.mpd"
length: 1
__proto__: Array(0)
handled: false
severity: 2
__proto__: Object



My
Server.jsfile :


var http = require('http');
var fs = require('fs');

console.log(__dirname);

var path='dash_segmentos/video.mpd';
fs.access(path, fs.constants.R_OK | fs.constants.W_OK, (err) => {
 if (err) {
 console.log("%s doesn't exist", path);
 } else {
 console.log('can read/write %s', path);
 }
});

const PORT=8080; 

fs.readFile('./player.html', function (err, html) {

 if (err) throw err; 

 http.createServer(function(request, response) { 
 response.setHeader("Access-Control-Allow-Headers", "authorization, content-type");
 response.setHeader("Access-Control-Allow-Origin", "*");
 response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
 response.writeHeader(200, {"Content-Type": "text/html"}); 
 response.write(html); 
 response.end();
 }).listen(PORT);
});



As you can see I've added CORS (I guess it's correct) and a console.log to see if it's in the proper location. Furthermore, I've verified that file is accessible with
fs.accessand it returnscan read/write dash_segmentos/video.mpdFor this reason, I'm sure I am in the correct path and referencing the right file.


The HTML code (
player.html) provided toServer.js:




 
 <code class="echappe-js"><script type="text/javascript"&#xA;src="https://cdnjs.cloudflare.com/ajax/libs/shaka-player/2.5.11/shaka-player.compiled.js"></script>
 
 

 



<script>&#xA;function initApp() { &#xA;shaka.polyfill.installAll(); &#xA;if (shaka.Player.isBrowserSupported()) { &#xA; initPlayer(); &#xA; } else { &#xA; console.error(&#x27;Browser not supported!&#x27;);&#xA; }}&#xA;&#xA;function initPlayer() { &#xA;var video = document.getElementById( &#x27;video&#x27; );&#xA;var player = new shaka.Player( video );&#xA; window.player = player; &#xA;player.addEventListener(&#x27;error&#x27;, onErrorEvent); &#xA;player.load(path).then(function (){&#xA; console.log(&#x27;Video loaded correctly&#x27;);&#xA; }).catch(onError);&#xA;&#xA;function onErrorEvent(event) {&#xA; onError(event.detail); &#xA; }&#xA;function onError(error) {&#xA; console.error(&#x27;Codigo de error: &#x27;, error.code, &#x27; en &#x27;, error);&#xA; }&#xA;}&#xA;</script>

<script>&#xA;var path=&#x27;dash_segmentos/video.mpd&#x27;;&#xA;//var path=&#x27;https://dash.akamaized.net/dash264/TestCases/2c/qualcomm/1/MultiResMPEG2.mpd&#x27;;&#xA;//the URL above is working! but it won&#x27;t read my local mpd&#xA;&#xA;document.addEventListener(&#x27;DOMContentLoaded&#x27;, initApp);&#xA;&#xA; </script>
 




I've tried changing the URL to an online resource and the player is properly working.



My fluent-ffmpeg command which generates the video is :



var ffmpeg = require('fluent-ffmpeg');

var grabacion = new ffmpeg();

grabacion.addInput('0')
.inputOptions(['-y -nostdin', '-f avfoundation', '-video_size 1280x720', '-framerate 30'])
.outputOptions(['-vcodec libx264', '-keyint_min 0', '-g 100', '-map 0:v', '-b:v 1000k', '-f dash',
 '-use_template 1', '-use_timeline 0', '-init_seg_name video0-$RepresentationID$-$Number$.mp4',
 '-media_seg_name video0-$RepresentationID$-$Number$.mp4','-single_file 0', '-remove_at_exit 0', '-window_size 20', '-seg_duration 4'])
.output('/path/to/files/dash_segmentos/video.mpd')
.run();



The mpd manifest file is :



<?xml version="1.0" encoding="utf-8"?>
<mpd xmlns="urn:mpeg:dash:schema:mpd:2011" profiles="urn:mpeg:dash:profile:isoff-live:2011" type="static" mediapresentationduration="PT26.7S" maxsegmentduration="PT4.0S" minbuffertime="PT13.2S">
 <programinformation>
 </programinformation>
 <servicedescription>
 </servicedescription>
 <period start="PT0.0S">
 <adaptationset contenttype="video" startwithsap="1" segmentalignment="true" bitstreamswitching="true" framerate="30000/1001" maxwidth="1280" maxheight="720" par="16:9">
 <representation mimetype="video/mp4" codecs="avc1.7a001f" bandwidth="1000000" width="1280" height="720" sar="1:1">
 <segmenttemplate timescale="1000000" duration="4000000" initialization="video0-$RepresentationID$-$Number$.mp4" media="video0-$RepresentationID$-$Number$.mp4" startnumber="1">
 </segmenttemplate>
 </representation>
 </adaptationset>
 </period>
</mpd>



Is something about ffmpeg ? Permissions ? Pixel format ? Encoding ? I've tried with other mpd file provided by my Raspberry Pi using video4linux (v4l) and it returns the same error !



I know that's a lot of code, but maybe you find it quicker than me. I guess it's a Shaka Player thing with the XML, but I can't explain how ffmpeg is wrongly creating XML code.



Thank you in advance !!


-
Perf Script Erroneous Dwarf Stacktrace Output
12 juin 2020, par TheAhmadI used the following command to sample backtraces for an
ffmpegbenchmark :


sudo perf record -d --call-graph dwarf,65528 -c 1000000 -e mem_load_uops_retired.l3_miss:u ffmpeg -i /media/ahmad/DATA/Videos/video.mp4 -threads 1 -vf spp out.mp4



As can be seen,
PEBSis not used, the stack size is set to the maximum and the sampling period is quite large. I also limited the thread count, but this is the first part ofperf script --no-demangleoutput :


ffmpeg 11750 6670.061261: 1000000 mem_load_uops_retired.l3_miss:u: 0 5080021 N/A|SNP N/A|TLB N/A|LCK N/A
 7fffeab68844 x264_pixel_avg_w16_avx2+0x4 (/usr/lib/x86_64-linux-gnu/libx264.so.152)

ffmpeg 11750 6670.274835: 1000000 mem_load_uops_retired.l3_miss:u: 0 5080021 N/A|SNP N/A|TLB N/A|LCK N/A
 7fffeab68844 x264_pixel_avg_w16_avx2+0x4 (/usr/lib/x86_64-linux-gnu/libx264.so.152)

ffmpeg 11750 6670.496159: 1000000 mem_load_uops_retired.l3_miss:u: 0 5080021 N/A|SNP N/A|TLB N/A|LCK N/A
 7fffeab8ef89 x264_pixel_sad_x4_16x16_avx2+0x49 (/usr/lib/x86_64-linux-gnu/libx264.so.152)

ffmpeg 11750 6670.852598: 1000000 mem_load_uops_retired.l3_miss:u: 0 5080021 N/A|SNP N/A|TLB N/A|LCK N/A
 7fffeaac97b3 pixel_memset+0x293 (inlined)
 7fffeaac97b3 plane_expand_border+0x293 (inlined)
 7fffeaac97b3 x264_frame_expand_border_filtered+0x293 (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 7fffeab463bc x264_fdec_filter_row+0x69c (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 7fffeab49523 x264_slice_write+0x1873 (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 7fffeab85285 x264_stack_align+0x15 (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 7fffeab45bdb x264_slices_write+0xfb (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 5555561e3d87 [unknown] ([heap])

ffmpeg 11750 6671.110007: 1000000 mem_load_uops_retired.l3_miss:u: 0 5080021 N/A|SNP N/A|TLB N/A|LCK N/A
 7fffeab6cdde x264_frame_init_lowres_core_avx2+0x8e (/usr/lib/x86_64-linux-gnu/libx264.so.152)

ffmpeg 11750 6671.463562: 1000000 mem_load_uops_retired.l3_miss:u: 0 5080021 N/A|SNP N/A|TLB N/A|LCK N/A
 7fffeaabf806 x264_macroblock_load_pic_pointers+0x886 (inlined)
 7fffeaabf806 x264_macroblock_cache_load+0x886 (inlined)
 7fffeaabf806 x264_macroblock_cache_load_progressive+0x886 (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 7fffeab49204 x264_slice_write+0x1554 (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 7fffeab85285 x264_stack_align+0x15 (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 7fffeab45bdb x264_slices_write+0xfb (/usr/lib/x86_64-linux-gnu/libx264.so.152)
 1c [unknown] ([unknown])



None of the backtraces are correct. Because none of them begin with
_startor__GI___clone. I also usedLBR, instead. But it has more size constraints and, therefore, not suitable. Any suggestions on how to get around the problem ?




UPDATE :



The problem happens for all events that I checked. When I used
mem_load_uops_retired.l3_missorLLC-load-missesthe problem was visible from the beginning. I also checked the output with thecyclesevent and everything worked fine, at the beginning. But after that, the same problem was seen.


Also, note that, the problem disappears when I sample only kernel
mem_load_uops_retired.l3_missevents.

-
bash - forcing globstar asterisk expansion when passed to loop
1er juillet 2020, par Kittywhiskers Van GoghI am attempting to write a script that finds the extension of all files within a directory and normalise them using
ffmpegto conform to a singular file format, codec and resolution.

#!/usr/bin/env bash

# We need to use globstar because we want to run this recursively (bash >4.0)
# This script won't run on macOS unless you install bash from homebrew
shopt -s globstar nullglob

# macOS doesn't have some stuff that we need, presuming you have homebrew already
# then run "brew install ffmpeg rename"
if ! [ -x "$(command -v ffmpeg)" ] || ! [ -x "$(command -v rename)" ]; then
 echo 'Required applications are absent, quitting :(' >&2
 exit 1
fi

# We need to know what file extensions we are dealing with
DISCOVERED_EXTENSIONS=$(find . -type f -name '*.*' | sed 's|.*\.||' | sort -u | tr '\n' ' ' | sed "s| | ./\**/*.|g" | rev | cut -c9- | rev | echo "./**/*.$(stdin)")

# Let's ignore newlines for now
IFS=$'\n'; set -f

# Within the loop
for f in $(echo $DISCOVERED_EXTENSIONS | tr ' ' '\n'); do
# Do nothing if there are no files to begin with
# if [ -z ${f+x} ]; then
# echo "no files found, exiting";
# else
# First get rid of all period/full-stops except the extension to prevent confusion
# rename "s/\.(?=[^.]*\.)/_/g" "$f";
# Now run conversion and save files with prefix processed_
# ffmpeg -i "$f" -vf scale=-1:720 -crf 18 \
# -c:v libx264 -preset veryslow -c:a libvo_aacenc -b:a 128k -c:s copy \
# "processed_${f%.*}.mp4";
# fi
 ls $f;
done

# No longer ignore newlines
unset IFS; set +f

# Stop using recursiveness after we're done
shopt -u globstar nullglob


I have commented out all the actual conversion code in an attempt to debug it, running this script alone, I get :


ls: ./**/*.avi: No such file or directory
ls: ./**/*.jpg: No such file or directory
ls: ./**/*.mkv: No such file or directory
ls: ./**/*.mp4: No such file or directory


It is passing
ls "./**/*.avi"instead ofls ./**/*.avi(because of no variable expansion). I attempted to use eval, envsubst and even used a customexpandfunction, to no avail

The result of
echo "$DISCOVERED_EXTENSIONS"is :

./**/*.avi ./**/*.jpg ./**/*.mkv ./**/*.mp4


ShellCheck objected to my lack of quotation marks but adding them in did not do anything. What changes can be recommended so that value of
$fis the result of glob expansion and not the expression itself ?

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