Hello, I am lost in creating a dash manifest for webm files and I hope you can help me.

I am creating webm files with ffmpeg:
```
ffmpeg -y -i $videoFilePath -c:v libvpx -keyint_min 150 -g 150 -tile-columns 4 -frame-parallel 1 `
-f webm -dash 1 -an -s 320x180 -b:v 500k ${dashFolder}/360p-30-700k.webm
```
When I now try to create the dash manifest, i get this:
```
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID audio1, computing from bitstream
[Dasher] Cannot find VPX config, using default vp08
[Dasher] Cannot find VPX config, using default vp08
[Dasher] Cannot find VPX config, using default vp08
[Dasher] Cannot find VPX config, using default vp08
[Dasher] codec parameters not known, cannot set codec string
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
[MP4Mux] Done writing segment 1 - estimated next fragment times start 0.002 end 2
Filters not connected:
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/360p-30-700k_dash_rep1init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:ps
sh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2AFCE0)
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/480p-30-1250k_dash_rep2init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:p
ssh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2B0540)
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/720p-30-2500k_dash_rep3init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:p
ssh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2B1DB0)
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/1080p-30-4500k_dash_rep4init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:
pssh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2B2610)
Error DASHing file: Internal Service Error
```

The command looks like this:
```
MP4Box -dash 4000 -frag 4000 -rap -profile onDemand -out ${dashFolder}/manifest.mpd `
${dashFolder}/360p-30-700k.webm `
${dashFolder}/480p-30-1250k.webm `
${dashFolder}/720p-30-2500k.webm `
${dashFolder}/1080p-30-4500k.webm `
${dashFolder}/audio.webm
```

I tried it with following. Some new webm files will be created but no manifest.
```
MP4Box -dash 4000 -frag 4000 -rap -profile onDemand -out ${dashFolder}/manifest.mpd --muxtype=webm `
${dashFolder}/360p-30-700k.webm `
${dashFolder}/480p-30-1250k.webm `
${dashFolder}/720p-30-2500k.webm `
${dashFolder}/1080p-30-4500k.webm `
${dashFolder}/audio.webm
```

How do i get the dash manifest? 
The manifest I can create with ffmpeg can not be read correctly by the videojs player . So I hope mp4box can create a working manifest. Thank you.
Need some help with dashing webm files
This is a GitHub Issue
repo:gpac
owner:gpac
Title : Need some help with dashing webm files
Issue date:

--- start body ---
Hello, I am lost in creating a dash manifest for webm files and I hope you can help me.

I am creating webm files with ffmpeg:
```
ffmpeg -y -i $videoFilePath -c:v libvpx -keyint_min 150 -g 150 -tile-columns 4 -frame-parallel 1 `
-f webm -dash 1 -an -s 320x180 -b:v 500k ${dashFolder}/360p-30-700k.webm
```
When I now try to create the dash manifest, i get this:
```
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID video1, computing from bitstream
[Dasher] No bitrate property assigned to PID audio1, computing from bitstream
[Dasher] Cannot find VPX config, using default vp08
[Dasher] Cannot find VPX config, using default vp08
[Dasher] Cannot find VPX config, using default vp08
[Dasher] Cannot find VPX config, using default vp08
[Dasher] codec parameters not known, cannot set codec string
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
[MP4Mux] No decoder specific info found for VP08
Failed to connect filter dasher PID video1 to filter mp4mx: BitStream Not Compliant
Blacklisting mp4mx as output from dasher and retrying connections
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
No filter chain found for PID video1 in filter dasher to any loaded filters - NOT CONNECTED
[MP4Mux] Done writing segment 1 - estimated next fragment times start 0.002 end 2
Filters not connected:
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/360p-30-700k_dash_rep1init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:ps
sh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2AFCE0)
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/480p-30-1250k_dash_rep2init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:p
ssh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2B0540)
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/720p-30-2500k_dash_rep3init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:p
ssh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2B1DB0)
fout (dst=C:/Users/AndreGa/Desktop/Converter/v7/ASM_1stSteps_ConfiguringParameterset_noUT/dash/1080p-30-4500k_dash_rep4init.mp4:gfopt:segdur=4000/1000:profile=onDemand:buf=1500:!check_dur:
pssh=v:subs_sidx=0:frag:xps_inband=no:psshs=moov:mime=video/mp4) (ptr=000001EA6E2B2610)
Error DASHing file: Internal Service Error
```

The command looks like this:
```
MP4Box -dash 4000 -frag 4000 -rap -profile onDemand -out ${dashFolder}/manifest.mpd `
${dashFolder}/360p-30-700k.webm `
${dashFolder}/480p-30-1250k.webm `
${dashFolder}/720p-30-2500k.webm `
${dashFolder}/1080p-30-4500k.webm `
${dashFolder}/audio.webm
```

I tried it with following. Some new webm files will be created but no manifest.
```
MP4Box -dash 4000 -frag 4000 -rap -profile onDemand -out ${dashFolder}/manifest.mpd --muxtype=webm `
${dashFolder}/360p-30-700k.webm `
${dashFolder}/480p-30-1250k.webm `
${dashFolder}/720p-30-2500k.webm `
${dashFolder}/1080p-30-4500k.webm `
${dashFolder}/audio.webm
```

How do i get the dash manifest? 
The manifest I can create with ffmpeg can not be read correctly by the videojs player . So I hope mp4box can create a working manifest. Thank you.
--- end body ---
