video has compressed and distorted audio and jerky frame-rate

[kamalakar108]

Dear all,

We are trying to hard code videos with UTF-8 Subtitles. Since the font is not properly depicted using ffmpeg for utf-8 subtitiles, a solution is brilliantly suggested by the Videoburger , member of the group.

When we make the videos using the code below, it is giving us Compressed and distored audio and jerky frame-rate.

Can any one suggest us what option we need to add to avoid this behaviour.

the code used by us is

ffmpeg -i 646.mp4 -i 646.ass -codec copy -s 720X480 -b:v 494k -b:a 192k temp.mkv
handbrakecli --subtitle 1 --subtitle-burned -i temp.mkv --rate 3 --vb 494k --ab 192k --width 720 --loose-anamorphic --quality 20 --nlmeans="light" -o 10646.mp4


Using the combained approach above we are able to get the UTF-8 font with out any issues. But with only either ffmpeg or hand brake cli alone we were not able to get it.

So kindly help us in addressing the final video's behaviour of Compressed and distored audio and jerky frame-rate

Regards
Kamalakar
Vanipedia
India

[johns0]

Please do not cross post the same thread,i deleted your other threads,just continue in this thread.

[kamalakar108]

Dear all,

Kindly find the video links of the original video and subtitled video using ffmpeg and hand brake

Original Video link
https://www.youtube.com/watch?v=YcTYWx8CaPA

Subtitled Video link
https://youtu.be/FT_shLmuxeM


Original video quality is much better. subtitled video quality is lost.

I am not sure what additional parameters we need to add to retain the same quality as original qualtiy for the following code


ffmpeg -i 646.mp4 -i 646.ass -codec copy -s 720X480 -b:v 494k -b:a 192k temp.mkv
handbrakecli --subtitle 1 --subtitle-burned -i temp.mkv --rate 3 --vb 494k --ab 192k --width 720 --loose-anamorphic --quality 20 --nlmeans="light" -o 10646.mp4

Can any one suggest us how to fix the problem

Regards
Kamalakar

[sneaker]

"--rate 3" is 3 fps. Omit the argument (or set to the same as source).

[kamalakar108]

Yes Sir, By Removing the --rate 3, we are able to get the problem fixed. Thanks a lot.

[kamalakar108]

Sir, When we used the following code the Video's audio quality is not as good as the original video. Since my tongue is not english, i dont know exactly what words/audio parameter to use when i say the audio quality is not as good as the original video.

Original Video
https://www.youtube.com/watch?v=rF6MVN3qbIs

Final video obtained by using the code
https://www.youtube.com/watch?v=0owunIjcIL8


The code we used to obtain the above output video is

ffmpeg -i 850.mp4 -i 850.ass -codec copy -s 720X480 -b:v 494k -b:a 192k temp.mkv
handbrakecli --subtitle 1 --subtitle-burned -i temp.mkv --vb 494k --ab 192k --width 720 --loose-anamorphic --quality 15 --nlmeans="light" -o 10850_3.mp4


Both the softwares are to be used to get hard code subtitles properly depicted in the video. This we cannot forego.
Kindly suggest as what additional parameter i need to use/change to retain the original video quality.

Regards
Kamalakar

[jagabo]

Change quality 15 to 1, 2, or 3. The smaller the number the higher the quality (and larger the resulting file).

[sneaker]

Just pass-thru (copy) the audio instead of encoding it:

handbrakecli --subtitle 1 --subtitle-burned  --vb 494k -E copy --width 720 --loose-anamorphic --quality 15  --nlmeans="light" -i temp.mkv -o 10850_3.mp4

That said, I'm surprised you would notice audio detoriation even when re-encoding. It's not something most people are able to hear.

[kamalakar108]

Sir,
I was looking at handbrake help and was surpised to see Video copy similar audio copy is not available in handbrake. Am i missing some thing or is it actually available.
Regards
Kamalakar

Following is the handbrake help file with destination and video options
Destination Options ----------------------------------------------------------

-o, --output <filename> Set destination file name
-f, --format <string> Select container format:
av_mp4
av_mkv
default: auto-detected from destination file name)
-m, --markers Add chapter markers
--no-markers Disable preset chapter markers
-O, --optimize Optimize MP4 files for HTTP streaming (fast start,
s.s. rewrite file to place MOOV atom at beginning)
--no-optimize Disable preset 'optimize'
-I, --ipod-atom Add iPod 5G compatibility atom to MP4 container
--no-ipod-atom Disable iPod 5G atom
-P, --use-opencl Use OpenCL where applicable


Video Options ----------------------------------------------------------------

-e, --encoder <string> Select video encoder:
x264
qsv_h264
x265
mpeg4
mpeg2
VP8
VP9
theora
--encoder-preset <string>
Adjust video encoding settings for a particular
speed/efficiency tradeoff (encoder-specific)
--encoder-preset-list <string>
List supported --encoder-preset values for the
specified video encoder
--encoder-tune <string>
Adjust video encoding settings for a particular
type of souce or situation (encoder-specific)
--encoder-tune-list <string>
List supported --encoder-tune values for the
specified video encoder
-x, --encopts <string> Specify advanced encoding options in the same
style as mencoder (all encoders except theora):
option1=value1ption2=value2
--encoder-profile <string>
Ensure compliance with the requested codec
profile (encoder-specific)
--encoder-profile-list <string>
List supported --encoder-profile values for the
specified video encoder
--encoder-level <string>
Ensures compliance with the requested codec
level (encoder-specific)
--encoder-level-list <string>
List supported --encoder-level values for the
specified video encoder
-q, --quality <float> Set video quality (e.g. 22.0)
-b, --vb <number> Set video bitrate in kbit/s (default: 1000)
-2, --two-pass Use two-pass mode
--no-two-pass Disable two-pass mode
-T, --turbo When using 2-pass use "turbo" options on the
first pass to improve speed
(works with x264 and x265)
--no-turbo Disable 2-pass mode's "turbo" first pass
-r, --rate <float> Set video framerate
(5/10/12/15/20/23.976/24/25/29.97/
30/48/50/59.94/60/72/75/90/100/120
or a number between 1 and 1000).
Be aware that not specifying a framerate lets
HandBrake preserve a source's time stamps,
potentially creating variable framerate video
--vfr, --cfr, --pfr Select variable, constant or peak-limited
frame rate control. VFR preserves the source
timing. CFR makes the output constant rate at
the rate given by the -r flag (or the source's
average rate if no -r is given). PFR doesn't
allow the rate to go over the rate specified
with the -r flag but won't change the source
timing if it's below that rate.
If none of these flags are given, the default
is --pfr when -r is given and --vfr otherwise

[jagabo]

You can't "copy" the video if you want burned in subtitles.

[Bernix]

Also it is not possible copy video in Handbrake/vidcoder.

Bernix

[kamalakar108]

Appreciate your replies for helping me.
Regards
Kamalakar

[kamalakar108]

Dear Sneaker Sir, --rate 3 is the culprit that corrupted both the video and audio files. When we removed that, Every thing came out good. Before posting this message, i missed to remove --rate 3 in one of files and hence we saw the issues.

When i realized this and removed it, with proper Video and audio bit rate given, every thing worked fine.

Thanks a lot for the help

Regards
Kamalakar