Audio lost in Handbrake during conversion from .webm to .mp4 format

[Cruisecontrol]

Hi. I've recorded some online videos in Chrome browser using Screencastify extension. I've downloaded the video to my desktop in .webm format as it is the only one Screencastify uses. When I play those videos back, the audio track is there and plays correctly, but after I've converted them to .mp4 using Handbrake or Vidcoder, there is no audio. I've gone through all of the settings and can't seem to find anything that would correct that. What am I missing? Thanks.

[LigH.de]

We are missing a detailed report how you set up your converters, if you configured the audio conversion part at all, which format, bitrate, etc.; and if they are able to create a log file about the conversion job, it would be useful too.

The MP4 container supports only a few selected audio formats, most important AAC and MP3 – but certainly neither Vorbis nor Opus (as probably used in WebM), therefore converting audio would be required. AAC would be optimal, but distributing ffmpeg or derived software including an AAC encoder in binary form is not allowed by their license, therefore you may have to step back to MP3 as audio format (LAME library).

[shekh]

Which license? Zeranoe build can encode to AAC, is it wrong?

[videobruger]

Which license? Zeranoe build can encode to AAC, is it wrong?

https://trac.ffmpeg.org/wiki/Encode/AAC

https://handbrake.fr/news.php?article=36

[El Heggunte]

.........
The MP4 container supports only a few selected audio formats, most important AAC and MP3 – but certainly neither Vorbis nor Opus (as probably used in WebM), therefore converting audio would be required.

Even though MP4Box and Haali Media Splitter have supported Vorbis in MP4 "since ages ago"...

[LigH.de]

It may depend on the specific available AAC encoder. Among the mentioned in Trac, FDK-AAC has the best quality, but like the simpler and older FAAC, both have a license not compatible to the GPL, therefore you may not distribute a binary mixed with other GPL compliant projects. You may only build it from sources for your private use.

The third mentioned library "aac" is not known to me in detail.

Current Zeranoe builds do not list using any AAC codec. I don't know how old the version is which you refer to, shekh. You will also have to read the generated help pages carefully, not all formats mentioned as "supported" are also included with a matching encoder library, it may be only decoded, or even only recognized.
_

Vorbis in MP4? Are you sure? Anyone please show me where MP4 specs allow this kind of audio stream ... if at all, then probably in a "private" substream. Dolby Digital (AC-3) is a very common extension, possibly even mentioned in MP4 specs, but Vorbis would really surprise me.

[shekh]

I just run quick command with current build (20160919)
"-c:a aac"
it worked.

Thanks for explaining about FDK-AAC. I am not as much concerned with best aac quality, assume ffmpeg internal aac encoder is all right.

[LigH.de]

OK, a really recent Zeranoe ffmpeg build contains a libav AAC encoder.

Now to use it in Handbrake or VidCoder as well, someone would need a just as recent build of them.

Still, we are waiting for 'Cruisecontrol' to report details as verbose as necessary.

[Cruisecontrol]

Thank you for your replies. I have listed as much info as I am aware of below:

I am using VidCoder v1.5.34.0(x64)
Windows 10 Home v10.0.14393 Build 14393
CPU: AMD A10-7890K Radeon R7
Settings from Audio tab:
- Codec: AAC (avcodec)
- Bitrate: Auto
- Target stream: All
- Mixdown: Stereo
- Gain: 0
- DRC: 0
- Sample Rate: Same as source
- Passthrough if possible (box is checked)
- + Add audio encoding (nothing listed)

Here are the log results from my latest attempt just now. Sorry about the smilies - they are supposed to be : D & : s

## VidCoder 1.5.34.0 (x64)
# Starting job 1/1
# Path: C:\Users\josep\Desktop\Untitled Screencast.webm
# Title: 1
# Range: All
# Worker ready: Service state is Opened on pipe VidCoderWorker.213b08b0-fd41-4a15-91ec-11dc041d02f2
# Connecting to process 2176 on pipe VidCoderWorker.213b08b0-fd41-4a15-91ec-11dc041d02f2
[10:24:09] hb_init: starting libhb thread
[10:24:09] CPU:
[10:24:09] - logical processor count: 4
[10:24:09] OpenCL device #1: Advanced Micro Devices, Inc. Spectre
[10:24:09] - OpenCL version: 2.0 AMD-APP (2117.8)
[10:24:09] - driver version: 2117.8 (VM)
[10:24:09] - device type: GPU
[10:24:09] - supported: YES
[10:24:09] Intel Quick Sync Video support: no
[10:24:09] hb_scan: path=C:\Users\josep\Desktop\Untitled Screencast.webm, title_index=1
libbluray/bdnav/index_parse.c:162: indx_parse(): error opening C:\Users\josep\Desktop\Untitled Screencast.webm/BDMV/index.bdmv
libbluray/bdnav/index_parse.c:162: indx_parse(): error opening C:\Users\josep\Desktop\Untitled Screencast.webm/BDMV/BACKUP/index.bdmv
libbluray/bluray.c:2182: nav_get_title_list(C:\Users\josep\Desktop\Untitled Screencast.webm) failed
[10:24:09] bd: not a bd - trying as a stream/file instead
libdvdnav: Using dvdnav version 5.0.1
libdvdread: Encrypted DVD support unavailable.
libdvdreadVDOpenFileUDF:UDFFindFile /VIDEO_TS/VIDEO_TS.IFO failed
libdvdreadVDOpenFileUDF:UDFFindFile /VIDEO_TS/VIDEO_TS.BUP failed
libdvdread: Can't open file VIDEO_TS.IFO.
libdvdnav: vm: failed to read VIDEO_TS.IFO
[10:24:09] dvd: not a dvd - trying as a stream/file instead
Input #0, matroska,webm, from 'C:\Users\josep\Desktop\Untitled Screencast.webm':
Duration: 02:03:21.20, start: 0.000000, bitrate: N/A
Stream #0.0: Video: vp8, yuv420p, 1920x950, PAR 1:1 DAR 192:95, 1k fps, 1k tbn (default)
Stream #0.1: Audio: [0][0][0][0] / 0x0000, 8000 Hz, 2 channels (default)
[10:24:09] dxva2xFindVideoServiceConversion failed
[10:24:09] scan: decoding previews for title 1
[10:24:09] scan: 10 previews, 1920x950, 23.976 fps, autocrop = 0/0/0/0, aspect 2.02:1, PAR 1:1
[10:24:09] libhb: scan thread found 1 valid title(s)
[10:24:10] 1 job(s) to process
[10:24:10] starting job
[10:24:10] sync: expecting 177451 video frames
[10:24:10] job configuration:
[10:24:10] * source
[10:24:10] + C:\Users\josep\Desktop\Untitled Screencast.webm
[10:24:10] + title 1, chapter(s) 1 to 1
[10:24:10] + container: matroska,webm
[10:24:10] * destination
[10:24:10] + C:\Users\josep\Desktop\Untitled Screencast.mp4
[10:24:10] + container: MPEG-4 (libavformat)
[10:24:10] * video track
[10:24:10] + decoder: vp8
[10:24:10] + filters
[10:24:10] + Framerate Shaper (0:27000000:1126125)
[10:24:10] + frame rate: same as source (around 23.976 fps)
[10:24:10] + Crop and Scale (1920:950:0:0:0:0)
[10:24:10] + source: 1920 * 950, crop (0/0/0/0): 1920 * 950, scale: 1920 * 950
[10:24:10] + loose anamorphic
[10:24:10] + storage dimensions: 1920 * 950, mod 2
[10:24:10] + pixel aspect ratio: 1 / 1
[10:24:10] + display dimensions: 1920 * 950
[10:24:10] + encoder: H.264 (libx264)
[10:24:10] + preset: veryfast
[10:24:10] + profile: main
[10:24:10] + level: 4.0
[10:24:10] + quality: 20.00 (RF)
[10:24:10] reader: first SCR -630 id 0x0 DTS 630
[10:24:10] encx264: min-keyint: 24, keyint: 240
[10:24:10] encx264: encoding at constant RF 20.000000
[10:24:10] encx264: unparsed options: level=4.0:ref=1:8x8dct=0:weightp=1ubme=2:mixed-refs=0:trellis=0:vbv-bufsize=25000:vbv-maxrate=20000:rc-lookahead=10
x264 [info]: x264 [info]: x264 [info]: [10:55:07] reader: done. 1 scr changes
[10:55:08] work: average encoding speed for job is 86.813232 fps
[10:55:08] mux: track 0, 161274 frames, 1985859366 bytes, 2146.52 kbps, fifo 2048
[10:55:08] sync: got 161274 frames, 177451 expected
[10:55:08] render: lost time: 0 (0 frames)
[10:55:08] render: gained time: 0 (0 frames) (0 not accounted for)
[10:55:08] vp8-decoder done: 161274 frames, 0 decoder errors, 0 drops
x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: x264 [info]: [10:55:08] libhb: work result = 0
# Job completed (Elapsed Time: 30m 59s)

[johns0]

When you select the video is there any audio displayed?If not then it's an audio type vidcoder doesn't recognize since the audio codecs isn't mentioned in the log.Post a mediainfo of the video,just paste the text in a post.

[Cruisecontrol]

When you select the video is there any audio displayed?If not then it's an audio type vidcoder doesn't recognize since the audio codecs isn't mentioned in the log.Post a mediainfo of the video,just paste the text in a post.

Thanks. I'm not sure what you mean by "audio type", but here's the info from MediaInfo:

General
Unique ID : 240969497283573712525939048670766797935 (0xB549097C1FD5A451B8F13761F9EF946F)
Complete name : C:\Users\josep\Desktop\Untitled Screencast.webm
Format : WebM
Format version : Version 4 / Version 2
File size : 4.40 GiB
Duration : 2 h 3 min
Overall bit rate : 5 108 kb/s
Writing application : w69b-mediawriter
Writing library : w69b-mediawriter
IsTruncated : Yes

Video
ID : 1
Format : VP8
Codec ID : V_VP8
Width : 1 920 pixels
Height : 950 pixels
Display aspect ratio : 2.021
Frame rate mode : Variable
Compression mode : Lossy
Default : Yes
Forced : No

Audio
ID : 2
Format : Opus
Codec ID : A_OPUS
Duration : 2 h 3 min
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 8 000 Hz
Bit depth : 16 bits
Compression mode : Lossy
Delay relative to video : -7 ms
Default : Yes
Forced : No

[Cruisecontrol]

When you select the video is there any audio displayed?If not then it's an audio type vidcoder doesn't recognize since the audio codecs isn't mentioned in the log.Post a mediainfo of the video,just paste the text in a post.

Oops. Never mind the part in my previous post where I said I didn't know what you meant by "audio type." My reading comprehension is fading with old age.

[videobruger]

Looks like OPUS decoding isn't supported in HandBrake (unless the nightly build has it). Use XmediaRecode instead.

[Cruisecontrol]

When you select the video is there any audio displayed?If not then it's an audio type vidcoder doesn't recognize since the audio codecs isn't mentioned in the log.Post a mediainfo of the video,just paste the text in a post.

Success! I looked at the mediainfo audio format and noticed that my .webm file used the Opus codec. Then I took a look at the VidCoder site again and saw that the Beta version now includes Opus. So, 2+2=4 and I downloaded the Beta version of VidCoder and ran my video again, et voila, the audio now works in the .mp4 file. Thanks for your help and for guiding me in the right direction. Thanks also to everyone who replied with their help and suggestions. Much appreciated!