Can't fast forward amd vce encoded files

[exus 16]

Hi, I've an issue with all amd vce encoded files, I'm using handbrake 1.3.3 to encode some files using amd vce h.265 (using a 6900xt gpu). When I play them on the emby web browser the transcode start fine but there's no way to fast forward, it just stops and start from the beginning (tested on chrome and firefox on different PCs). If i change only the encode settings inside handbrake and use cpu h.265 to encode the file everything works fine inside emby.

When I play the vce encoded file inside emby theater there are no issue (but it's not transcoding the file, just direct play)

log_error_amd_vce.txt

[Luke 42081]

Hi @exus, try setting these back to default:

>>>>>  Non-Default Encoder Parameters
Warning EncoderParametersH264LibX.ConstantRateFactor: Original: 23 Actual: 10
Warning EncoderParametersH264LibX.Preset: Original: veryfast Actual: slow

And then see how it compares. Thanks.

[exus 16]

I changed the values back to default, same error

log_error_amd_vce2.txt

[exus 16]

I encoded two sample files if you want to try.. one encoded using cpu and another encoded usic amd vce (all the others encoding settings are the same).

When transcoded to h264 they both start but I can't fast forward the vce one.

 

samples.zip

Edited July 19, 2021 by exus

[Carlo 4561]

Interesting.  On my system I can play both back via web (transcoded) and can jump ahead just fine.

I tried this both with software and hardware transcoding (Nvidia 1650).

[exus 16]

Can you try to resume the playback  of the vce encoded file using software transcode on web browser and see if it works?

I'm doing some tests and when I fast forward just few seconds (on a frame that's probably already transcoded) it works fine, If a fast forward much more it stops and error comes out. With the "resume from" it crashes immediately.

 

Edited July 19, 2021 by exus

[Carlo 4561]

I can reproduce this on my Synology 920+ using software only doing a resume.

This is likely due to bad encoding of the file which ffmpeg is able to compensate for when it starts at the beginning of the file but can't "fix" when it has to jump into the file to start transcoding.

The ffmpeg log file for the transcode is full of media errors when doing the resume.

As a test try using https://www.xmedia-recode.de/en/ Recode instead of Handbrake with your AMD and see if this has the same issues. This will help determine if it's a processor issue or encoding software issue.

I hate to say it but most people try and avoid AMD for video conversion as QuickSync and Nvidia are the preferred GPUs to use and basically just work.

[speechles 2055]

When you remux it should put the seek head at the front. Heads go on the front. Some encoders put the seek head as a tail for some unknown reason. That might be what this is.

When encoded at the head it is within the "header". Anything with a head should be in the "head"er. That is why they call it that. The player reads the header before playback of the file.

When encoded at the tail the header does not contain seek data. Not until the entire file has been read/buffered to the client and it can read the extra data appended at the tail and recognize it is the missing seek data and make use of it.

Handbrake is notorious for storing header details in the tail of the file as extra data.

Edited July 19, 2021 by speechles

[exus 16]

I just tried with xmedia recode, same issue

I know amd is not the best choice, I always used Nvidia or CPU to encode, I just built a new pc and I was only able to find an amd gpu

How can I check the "seek head" you are talking about speechles?

[speechles 2055]

1 minute ago, exus said:

I just tried with xmedia recode, same issue

I know amd is not the best choice, I always used Nvidia or CPU to encode, I just built a new pc and I was only able to find an amd gpu

How can I check the "seek head" you are talking about speechles?

Simple Remux with MKVToolNixGui. Copy all streams. Simply make a new MKV container with a new header. That is all.

MKVToolNix GUI does the same as MKClean when Remux and gives a GUI.

 

[speechles 2055]

1 minute ago, exus said:

I just tried with xmedia recode, same issue

I know amd is not the best choice, I always used Nvidia or CPU to encode, I just built a new pc and I was only able to find an amd gpu

How can I check the "seek head" you are talking about speechles?

Simple Remux with MKVToolNixGui. Copy all streams. Simply make a new MKV container with a new header. That is all.

MKVToolNix GUI does the same as MKClean when Remux and gives a GUI.

mkclean

mkclean is a command line tool to clean and optimize Matroska (.mkv / .mka / .mks / .mk3d) and WebM (.webm / .weba) files that have already been muxed. It reorders the elements with the Cues at the front, so your Matroska files are ready to be streamed efficiently over the web. It also removes elements not found in the Matroska specs and the extra Meta Seek list of Clusters that some program add to their file. It can also optionally remux the Cluster blocks to start each boundary with a keyframe and the matching audio/subtitle blocks for that keyframe.

[exus 16]

I just tried with mkvtoolnix, with the new mkv file I can fast forward without issues but the "resume from" it's still not working (no errors it's not starting at all, stuck at 00:00)

 

h265_GPU_encodeMKV.zip ffmpeg-transcode-7a07004a-3ce8-43d3-b664-51d8572e7ca3_1.txt

[Carlo 4561]

For kicks/testing try encoding to an MP4 file vs MKV but make sure to put the MOOV atom at the start of the file.
It's possible that could make a difference as well.

[exus 16]

I tried to encode an mp4 and a mkv with the additional option -movflags +faststart (is this the right option?), no changes. both fast forward and resume not working. 

 

[Carlo 4561]

OK thanks for trying those settings.  It would appear the AMD H.265 encode isn't as compatible as it should be.

[exus 16]

I was checking my library and I realized that only the files I encoded from the 26th of June have this issue, I've files created the 20th that do not have this problem (and previous that date all files run fine).

I checked the event log to see my driver update history, I had the 21.5.2 driver until the 22 june so I reinstalled it. Fast forward and resume with 21.5.2 works fine (at least with chrome, on firefox i still have some issues with the "resume"). It's definitely an amd driver issue. Starting from 21.6.1 up to the latest 21.7.1 the fast forward and resume it's not working

[Carlo 4561]

Nice detective work.  Have you reported this to AMD?

[exus 16]

Yes, I just reported it on their Bug tool, I hope they'll read it