I'm stumped with encoding videos into a dash compliant format. I'm going from .mp4 to .webm

Firstly, I am running OS X and ffmpeg 2.5.4.

Here's the encoding commands I am using in my test (I got these from here):

ffmpeg -i IMG_0113.mp4 -c:v libvpx-vp9 -s 160x90 -b:v 25k -g 1 -tile-columns 4 -frame-parallel 1 -an -f webm -dash 1 video_160x90_25k.webm

ffmpeg -i IMG_0113.mp4 -c:v libvpx-vp9 -s 160x90 -b:v 50k -g 1 -tile-columns 4 -frame-parallel 1 -an -f webm -dash 1 video_160x90_50k.webm

ffmpeg -i IMG_0113.mp4 -vn -acodec libvorbis -ab 128k  -dash 1 audio_128k.webm

ffmpeg -f webm_dash_manifest -i video_160x90_25k.webm -f webm_dash_manifest -i video_160x90_50k.webm -f webm_dash_manifest -i audio_128k.webm -c copy -map 0 -map 1 -map 2 -f webm_dash_manifest -adaptation_sets "id=0,streams=0,1 id=1,streams=2" manifest.mpd

Secondly, the problem is not with my server, as I have downloaded the samples from here, and they work 100% on the dash.js player when served from my local server.

Please could someone out there point me in the right direction? Or provide a sample of the ffmpeg commands used to get the output format correct.

Thanks, Dean.

Ok, here goes, managed to solve this. Hopefully this will save someone else some hassles.

Firstly, here's the solution.

Step 1: (strip audio from video, and create single audio file)

ffmpeg -i IMG_0113.mp4 -c:v libvpx -s 160x90 -threads 4 -b:v 25k -tile-columns 4 -frame-parallel 1 -an -keyint_min 30 -g 30 -f webm video_160x90_25k.webm

ffmpeg -i IMG_0113.mp4 -c:v libvpx -s 160x90 -threads 4 -b:v 50k -tile-columns 4 -frame-parallel 1 -an -keyint_min 30 -g 30 -f webm video_160x90_50k.webm

ffmpeg -i IMG_0113.mp4 -vn -acodec libvorbis -ab 128k audio_128k.webm

Step 2: (using sample_muxer from the libwebm project available here, to create the video cue points)

mkvmuxer_sample -i video_160x90_25k.webm -o video_160x90_25k_cued.webm

mkvmuxer_sample -i video_160x90_50k.webm -o video_160x90_50k_cued.webm

Step 3: (Use ffmpeg to create the audio cue points)

ffmpeg -i audio_128k.webm -vn -acodec libvorbis -ab 128k -dash 1 audio_128k_cued.webm

Step 4: (Use ffmpeg to create the webm dash manifest file .mpd)

ffmpeg -f webm_dash_manifest -i video_160x90_25k_cued.webm -f webm_dash_manifest -i video_160x90_50k_cued.webm -f webm_dash_manifest -i audio_128k_cued.webm -c copy -map 0 -map 1 -map 2 -f webm_dash_manifest -adaptation_sets "id=0,streams=0,1 id=1,streams=2" manifest.mpd

Secondly, here's the explanation.

ffmpeg (my version atleast), was not creating the cue points in the video files correctly (when adding the -dash 1) param. I determined this by probing the video files, and by understanding the webm file format (read this, if you'd like to know more).

I then stumbled upon sample_muxer from reading this page, and decided to see if it would better handle the video cue points that ffmpeg wasn't getting right. Whoop Whoop, it did!

I noticed that the cue points in the extracted audio file from ffmpeg (using the -dash 1 param), were being created correctly!

The ffmpeg generation of the webm dash manifest is also working nicely!

For playing back the video, I found shaka-player worked best but I could not use it as I required video playback from a cefpython container and the shaka-player did not work on the latest cef (chromium embedded framework) included in the cefpython release.

I then wrote my own player based off of this helpful site from google

Anyway, hope this helps someone