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• avformat/dashdec : Remove redundant checks

  19 septembre 2020, par Andreas Rheinhardt

  avformat/dashdec : Remove redundant checks
  This commit removes two always-true checks as well as a dead default
  
  case of a switch. The check when parsing manifests is always true,
  
  because we now jump to the cleaning code in case the format of the
  
  representation is unknown. The default case of the switch is dead,
  
  because the type of the representation is already checked at the
  
  beginning of parse_manifest_representation(). The check when reading
  
  the header is dead, because we error out if an error happened before.
  Reviewed-by : Steven Liu <lq@chinaffmpeg.org>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavformat/dashdec.c

• avcodec/utils : Only call codec->close if init has been called

  24 septembre 2020, par Andreas Rheinhardt

  avcodec/utils : Only call codec->close if init has been called
  avcodec_open2() also called the AVCodec's close function if an error
  
  happened before init had ever been called if the AVCodec has the
  
  FF_CODEC_CAP_INIT_CLEANUP flag set. This is against the documentation of
  
  said flag : "The codec allows calling the close function for deallocation
  
  even if the init function returned a failure."
  E.g. the SVQ3 decoder is not ready to be closed if init has never been
  
  called.
  Fixes : NULL dereference
  
  Fixes : 25762/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SVQ3_fuzzer-5716279070294016
  Found-by : continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
  Reviewed-by : Paul B Mahol <onemda@gmail.com>
  
  Reviewed-by : Michael Niedermayer <michael@niedermayer.cc>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavcodec/utils.c

• Express - FFMPEG : Serve transcoded video instead of static video file

  30 septembre 2020, par No stupid questions

  I am creating a website to host videos downloaded on my computer online. However, many of these videos are not in a web friendly format (like .mkv or .flv). It is not an option to convert these files on the disk and then serve them as static files, converting needs to be done live by the server. I want to transcode these videos with ffmpeg to a web friendly format like webm.

  


  So far, I have been able to somewhat successfully transcode a video and serve it :

  


  import express from 'express';
import cors from 'cors';
import ffmpeg from 'fluent-ffmpeg';

const app = express();

app.use(cors());
app.use(express.json());

app.use('/static/videos', globalPasswordMiddleware, (req, res) => {
    res.contentType('webm');
    const videoPath = path.join('C:/videos', decodeURIComponent(req.path));
    ffmpeg(videoPath)
        .format('webm')
        .on('end', function () {
            console.log('file has been converted succesfully');
        })
        .on('error', function (err) {
            console.log('an error happened: ' + err.message);
        })
        .pipe(res, { end: true });
});


  


  However, I am still encountering three different issues :

  


  Firstly, while this code seems to work for transcoding something like a flash video into webm, there are still a number of videos I cannot get to play. For example, a number of videos that play in Chrome will still not play in Firefox or a number of videos that play on my PC won't on my ancient iPad. Are there more arguments I need to be passing to ffmpeg to transcode the video in a way that it will work on a greater number or devices/browsers ?

  


  Second, there is no ability to seek on the video or see how much time remains. When viewing a transcoded video it behaves more like a livestream than if I were serving it as a static file. How can I fix this ?

  


  And finally third, the transcoding is massively slow. Running in production mode, video playback has to buffer for a few seconds every five or so seconds. I am aware transcoding video is an intense process but I believe given my computer's hardware (i9 9900K) and how much faster it is at transcoding videos on Plex that I should be able to transcode videos faster than this.