问题
I am converting a .avi file to .flv file using ffmpeg. As it takes a long time to convert a file I would like to display a progress bar. Can someone please guide me on how to go about the same.
I know that ffmpeg somehow has to output the progress in a text file and I have to read it using ajax calls. But how do I get ffmpeg to output the progress to the text file?
Thank you very much.
回答1:
I've been playing around with this for a few days. That "ffmpegprogress" thing helped, but it was very hard to get to work with my set up, and hard to read the code.
In order to show the progress of ffmpeg you need to do the following:
- run the ffmpeg command from php without it waiting for a response (for me, this was the hardest part)
- tell ffmpeg to send it's output to a file
- from the front end (AJAX, Flash, whatever) hit either that file directly or a php file that can pull out the progress from ffmpeg's output.
Here's how I solved each part:
1. I got the following idea from "ffmpegprogress". This is what he did: one PHP file calls another through an http socket. The 2nd one actually runs the "exec" and the first file just hangs up on it. For me his implementation was too complex. He was using "fsockopen". I like CURL. So here's what I did:
$url = "http://".$_SERVER["HTTP_HOST"]."/path/to/exec/exec.php";
curl_setopt($curlH, CURLOPT_URL, $url);
$postData = "&cmd=".urlencode($cmd);
$postData .= "&outFile=".urlencode("path/to/output.txt");
curl_setopt($curlH, CURLOPT_POST, TRUE);
curl_setopt($curlH, CURLOPT_POSTFIELDS, $postData);
curl_setopt($curlH, CURLOPT_RETURNTRANSFER, TRUE);
// # this is the key!
curl_setopt($curlH, CURLOPT_TIMEOUT, 1);
$result = curl_exec($curlH);
Setting CURLOPT_TIMEOUT to 1 means it will wait 1 second for a response. Preferably that would be lower. There is also the CURLOPT_TIMEOUT_MS which takes milliseconds, but it didn't work for me.
After 1 second, CURL hangs up, but the exec command still runs. Part 1 solved.
BTW - A few people were suggesting using the "nohup" command for this. But that didn't seem to work for me.
*ALSO! Having a php file on your server that can execute code directly on the command line is an obvious security risk. You should have a password, or encode the post data in some way.
2. The "exec.php" script above must also tell ffmpeg to output to a file. Here's code for that:
exec("ffmpeg -i path/to/input.mov path/to/output.flv 1> path/to/output.txt 2>&1");
Note the "1> path/to/output.txt 2>&1". I'm no command line expert, but from what I can tell this line says "send normal output to this file, AND send errors to the same place". Check out this url for more info: http://tldp.org/LDP/abs/html/io-redirection.html
3. From the front end call a php script giving it the location of the output.txt file. That php file will then pull out the progress from the text file. Here's how I did that:
// # get duration of source
preg_match("/Duration: (.*?), start:/", $content, $matches);
$rawDuration = $matches[1];
// # rawDuration is in 00:00:00.00 format. This converts it to seconds.
$ar = array_reverse(explode(":", $rawDuration));
$duration = floatval($ar[0]);
if (!empty($ar[1])) $duration += intval($ar[1]) * 60;
if (!empty($ar[2])) $duration += intval($ar[2]) * 60 * 60;
// # get the current time
preg_match_all("/time=(.*?) bitrate/", $content, $matches);
$last = array_pop($matches);
// # this is needed if there is more than one match
if (is_array($last)) {
$last = array_pop($last);
}
$curTime = floatval($last);
// # finally, progress is easy
$progress = $curTime/$duration;
Hope this helps someone.
回答2:
There is an article in Russian which describes how to solve your problem.
The point is to catch Duration value before encoding and to catch time=... values during encoding.
--skipped--
Duration: 00:00:24.9, start: 0.000000, bitrate: 331 kb/s
--skipped--
frame= 41 q=7.0 size= 116kB time=1.6 bitrate= 579.7kbits/s
frame= 78 q=12.0 size= 189kB time=3.1 bitrate= 497.2kbits/s
frame= 115 q=13.0 size= 254kB time=4.6 bitrate= 452.3kbits/s
--skipped--
回答3:
FFmpeg uses stdout for outputing media data and stderr for logging/progress information. You just have to redirect stderr to a file or to stdin of a process able to handle it.
With a unix shell this is something like:
ffmpeg {ffmpeg arguments} 2> logFile
or
ffmpeg {ffmpeg arguments} 2| processFFmpegLog
Anyway, you have to run ffmpeg as a separate thread or process.
回答4:
It’s very simple if you use the pipeview command. To do this, transform
ffmpeg -i input.avi {arguments}
to
pv input.avi | ffmpeg -i pipe:0 -v warning {arguments}
No need to get into coding!
回答5:
You can do it with ffmpeg's -progress argument and nc
WATCHER_PORT=9998
DURATION= $(ffprobe -select_streams v:0 -show_entries "stream=duration" \
-of compact $INPUT_FILE | sed 's!.*=\(.*\)!\1!g')
nc -l $WATCHER_PORT | while read; do
sed -n 's/out_time=\(.*\)/\1 of $DURATION/p')
done &
ffmpeg -y -i $INPUT_FILE -progress localhost:$WATCHER_PORT $OUTPUT_ARGS
回答6:
Sadly, ffmpeg itself still cannot show a progress bar – also, many of the aforementioned bash- or python-based stop-gap solutions have become dated and nonfunctional.
Thus, i recommend giving the brand-new ffmpeg-progressbar-cli a try:
It's a wrapper for the ffmpeg executable, showing a colored, centered progress bar and the remaining time.
Also, it's open-source, based on Node.js and actively developed, handling most of the mentioned quirks (full disclosure: i'm its current lead developer).
回答7:
javascript should tell php to start converting [1] and then do [2] ...
[1] php: start conversion and write status to file (see above):
exec("ffmpeg -i path/to/input.mov path/to/output.flv 1>path/to/output.txt 2>&1");
For the second part we need just javascript to read the file. The following example uses dojo.request for AJAX, but you could use jQuery or vanilla or whatever as well :
[2] js: grab the progress from the file:
var _progress = function(i){
i++;
// THIS MUST BE THE PATH OF THE .txt FILE SPECIFIED IN [1] :
var logfile = 'path/to/output.txt';
/* (example requires dojo) */
request.post(logfile).then( function(content){
// AJAX success
var duration = 0, time = 0, progress = 0;
var resArr = [];
// get duration of source
var matches = (content) ? content.match(/Duration: (.*?), start:/) : [];
if( matches.length>0 ){
var rawDuration = matches[1];
// convert rawDuration from 00:00:00.00 to seconds.
var ar = rawDuration.split(":").reverse();
duration = parseFloat(ar[0]);
if (ar[1]) duration += parseInt(ar[1]) * 60;
if (ar[2]) duration += parseInt(ar[2]) * 60 * 60;
// get the time
matches = content.match(/time=(.*?) bitrate/g);
console.log( matches );
if( matches.length>0 ){
var rawTime = matches.pop();
// needed if there is more than one match
if (lang.isArray(rawTime)){
rawTime = rawTime.pop().replace('time=','').replace(' bitrate','');
} else {
rawTime = rawTime.replace('time=','').replace(' bitrate','');
}
// convert rawTime from 00:00:00.00 to seconds.
ar = rawTime.split(":").reverse();
time = parseFloat(ar[0]);
if (ar[1]) time += parseInt(ar[1]) * 60;
if (ar[2]) time += parseInt(ar[2]) * 60 * 60;
//calculate the progress
progress = Math.round((time/duration) * 100);
}
resArr['status'] = 200;
resArr['duration'] = duration;
resArr['current'] = time;
resArr['progress'] = progress;
console.log(resArr);
/* UPDATE YOUR PROGRESSBAR HERE with above values ... */
if(progress==0 && i>20){
// TODO err - giving up after 8 sec. no progress - handle progress errors here
console.log('{"status":-400, "error":"there is no progress while we tried to encode the video" }');
return;
} else if(progress<100){
setTimeout(function(){ _progress(i); }, 400);
}
} else if( content.indexOf('Permission denied') > -1) {
// TODO - err - ffmpeg is not executable ...
console.log('{"status":-400, "error":"ffmpeg : Permission denied, either for ffmpeg or upload location ..." }');
}
},
function(err){
// AJAX error
if(i<20){
// retry
setTimeout(function(){ _progress(0); }, 400);
} else {
console.log('{"status":-400, "error":"there is no progress while we tried to encode the video" }');
console.log( err );
}
return;
});
}
setTimeout(function(){ _progress(0); }, 800);
回答8:
Calling php's system function blocks that thread, so you'll need to spawn off 1 HTTP request for performing the conversion, and another polling one for reading the txt file, that's being generated.
Or, better yet, clients submit the video for conversion and then another process is made responsible for performing the conversion. That way the client's connection won't timeout while waiting for the system call to terminate. Polling is done in the same way as above.
回答9:
If you just need hide all info and show default progress like ffmpeg in last line, you can use -stats option:
ffmpeg -v warning -hide_banner -stats ${your_params}
回答10:
Had problems with the second php part. So I am using this instead:
$log = @file_get_contents($txt);
preg_match("/Duration:([^,]+)/", $log, $matches);
list($hours,$minutes,$seconds,$mili) = split(":",$matches[1]);
$seconds = (($hours * 3600) + ($minutes * 60) + $seconds);
$seconds = round($seconds);
$page = join("",file("$txt"));
$kw = explode("time=", $page);
$last = array_pop($kw);
$values = explode(' ', $last);
$curTime = round($values[0]);
$percent_extracted = round((($curTime * 100)/($seconds)));
Outputs perfectly.
Would like to see something for multiple uploads for another progress bar. This passing for the current file for one percentage. Then an overall progress bar. Almost there.
Also, if people are having a hard time getting:
exec("ffmpeg -i path/to/input.mov path/to/output.flv 1> path/to/output.txt 2>&1");
To work.
Try:
exec("ffmpeg -i path/to/input.mov path/to/output.flv 1>path/to/output.txt 2>&1");
"1> path" to "1>path" OR "2> path" to "2>path"
Took me awhile to figure it out. FFMPEG kept failing. Worked when I changed to no space.
来源：https://stackoverflow.com/questions/747982/can-ffmpeg-show-a-progress-bar