# Error playing recorded videos without transcoding

**URL:** <https://discourse.lynckia.com/t/error-playing-recorded-videos-without-transcoding/27>\
**Category:** Uncategorized\
**Created:** [October 16, 2014, 11:00am UTC](https://discourse.lynckia.com/t/error-playing-recorded-videos-without-transcoding/27 "2014-10-16T11:00:53Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Sergio\_Gomez](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@Sergio\_Gomez](https://discourse.lynckia.com/u/Sergio_Gomez)\
**Post date:** [October 16, 2014, 11:00am UTC](https://discourse.lynckia.com/t/error-playing-recorded-videos-without-transcoding/27/1 "2014-10-16T11:00:53Z")

</div>

Hi,

We have developed a video conference application with Licode and we have  
now a problem. We record the streams but we would like to see them  
instantly when they finished being recorded without transcoding or  
postprocessing them. For that we use simple HTML5 video tag but the mkv  
files that Licode makes don’t work (HTML5 video element fires onerror event  
with code 3 (error decoding)).  
Then we transcode with ffmpeg one of these videos and we realised that this  
new video works (id plays fine). We use:

ffmpeg -i video.mkv -s 640x480 -vcodec vp8 -acodec pcm\_mulaw -c:a copy

> result.mkv

If i’m not wrong, Licode records in VP8 and pcmu too, so both videos use  
same codecs, we used ffmpeg -i on both files and we get:

For Licode’s one:

libavutil 52. 38.100 / 52. 38.100

> libavcodec 55. 18.102 / 55. 18.102  
> libavformat 55. 12.100 / 55. 12.100  
> libavdevice 55. 3.100 / 55. 3.100  
> libavfilter 3. 79.101 / 3. 79.101  
> libswscale 2. 3.100 / 2. 3.100  
> libswresample 0. 17.102 / 0. 17.102  
> libpostproc 52. 3.100 / 52. 3.100  
> Guessed Channel Layout for Input Stream #0.1 : mono  
> Input #0, matroska,webm, from ‘video.mkv’:  
> Metadata:  
> ENCODER : Lavf54.20.4  
> Duration: 00:00:10.59, start: 0.000000, bitrate: 358 kb/s  
> Stream #0:0: Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 30 fps, 30  
> tbr, 1k tbn, 1k tbc (default)  
> Stream #0:1: Audio: pcm\_mulaw ([7][0][0][0] / 0x0007), 8000 Hz, mono,  
> s16, 64 kb/s (default)

For transcoded video:

libavutil 52. 38.100 / 52. 38.100

> libavcodec 55. 18.102 / 55. 18.102  
> libavformat 55. 12.100 / 55. 12.100  
> libavdevice 55. 3.100 / 55. 3.100  
> libavfilter 3. 79.101 / 3. 79.101  
> libswscale 2. 3.100 / 2. 3.100  
> libswresample 0. 17.102 / 0. 17.102  
> libpostproc 52. 3.100 / 52. 3.100  
> Guessed Channel Layout for Input Stream #0.1 : mono  
> Input #0, matroska,webm, from ‘result.mkv’:  
> Metadata:  
> ENCODER : Lavf55.12.100  
> Duration: 00:00:06.07, start: 0.000000, bitrate: 358kb/s  
> Stream #0:0: Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 30 fps, 30  
> tbr, 1k tbn, 1k tbc (default)  
> Stream #0:1: Audio: pcm\_mulaw ([7][0][0][0] / 0x0007), 8000 Hz, mono,  
> s16, 64 kb/s (default)

They only differ in the encoder. So can we achieve the second file while  
recording without postprocess it? Or can we use another codec which get  
played well in HTML video elements?

Thank you.

Sergio.