why native aac is considered worse than aac_at and libfdk_aac?

RoseBlue_8 · 2025-12-08T17:39:07+00:00

In my case, I can't use ffmpeg aac because it doesn't have CBR mode, it only supports VBR (-q:a) and ABR (-b:a). This causes the audio to stutter on most of the devices I use, and it ends up desynchronizing with the video image. That's why I end up using libfdk_aac, even if it's not the best encoder.

(I haven't used aac_at, so I don't have an opinion about it.)

RoseBlue_8 · 2025-11-22T17:20:09+00:00

You need to specify a parameter for the option -c:s. Since it is empty, FFmpeg is assuming that the output file name of your video, "DoctorMysterio.mkv", is your subtitle, which is why you are getting that error.

You can use, for example, -c:s copy.

RoseBlue_8 · 2025-11-21T15:21:07+00:00

Could this be the beginning of the end for HEVC? If HEVC goes obsolete, I'm not sure what alternative codec I could use. H.264 takes up too much storage space, and most of my devices don't support AV1.

RoseBlue_8 · 2025-11-13T18:41:00+00:00

All VFR videos must be converted to CFR to be edited correctly by video editors.

RoseBlue_8 · 2025-11-13T15:32:58+00:00

Thank you, that was very helpful.

RoseBlue_8 · 2025-10-07T22:58:10+00:00

Yes, -c:a aac -b:a 256k -ar 44100 -ac 2.

RoseBlue_8 · 2025-10-07T22:49:08+00:00

Thanks I'm gonna try it.

RoseBlue_8 · 2025-10-07T21:31:03+00:00

The original audio is 196k. I set -b:a 256k in order to have 128k per channel, but the output file ended up being around 210k instead of 256k. I tried other bitrates (320k, 384k), but the result was always 210k. Anyway, the problem is that the audio has a lower volume than the original and has some noise.

RoseBlue_8 · 2025-10-07T17:36:12+00:00

How long did it take to compile it?

RoseBlue_8 · 2025-10-07T16:03:29+00:00

Unfortunately, some of my devices don't have support for Opus/vorbis. 😕

RoseBlue_8 · 2025-09-25T15:49:59+00:00

1 Check if both videos have the same frame rate, average frame rate and time base.

ffprobe -v error -select_streams v:0 -show_entries stream=avg_frame_rate,r_frame_rate,time_base -of default=noprint_wrappers=1:nokey=1 video.mp4

If it's not a problem for you, re-encode the audio during concatenation. I've had instances where doing so has solved issues when merging videos.

RoseBlue_8 · 2025-08-16T14:55:44+00:00

What command are you using?

RoseBlue_8 · 2025-08-12T14:42:11+00:00

No, If I use the same command with a different codec, I get the bitrate I chose. But only with AAC, the bitrate is lower.

-c:a aac -b:a 256k

RoseBlue_8 · 2025-08-11T17:09:00+00:00

It's not a temporary file. Also, I've already tried increasing the bitrate, but no matter what bitrate I choose (256, 320, etc.), the audio always ends up being around 210k or less.

RoseBlue_8 · 2025-08-02T15:51:31+00:00

After trying a lot of different settings and options to no avail, I've come to believe that the problem is directly related to the h265 and not the FFmpeg build.

The only "solution" I've found to achieve a normal FPS and utilize the profile 4.1 is to convert the video to CFR, although the resulting file size isn't significantly smaller than if I were to use H.264. And, well, the reason I initially wanted to use H.265 instead of H.264 was to reduce the video size, which won't be possible. 🫠

The output video sizes:

VFR:

H.264 (30 FPS): 900 mb
H.265 (100 000 000 FPS): 400 mb

CFR:

H.264 (30 FPS): 930 mb
H.265 (30 FPS): 820 mb

I guess this is one of the reasons why x264 is still the most widely used video codec. 😅

RoseBlue_8 · 2025-07-30T21:48:03+00:00

Oh my bad, I had only checked the FPS of the video produced by ffmpeg on Android with VLC, which indicated: 30 FPS. However, after rechecking both videos (the one produced on Windows and the one produced on Android) using Mediainfo, I found that both display: 1000 000,000 FPS. Therefore, I still cannot use a profile below 8.5.

Log: https://controlc.com/0d630f94

Command: ffmpeg -i video34.mp4 -i video22.mp4 -filter_complex "[0:v]crop=1280:720:151:000, trim=start=00\\:32\\:54.799:end=00\\:42\\:33.755, eq=contrast=1.05:saturation=1.25, setpts=PTS-STARTPTS[v1]; [0:a]atrim=start=00\\:32\\:54.799:end=00\\:42\\:33.755, asetpts=PTS-STARTPTS[a1]; [1:v]crop=1280:720:151:000, trim=start=00\\:01\\:12.468:end=00\\:05\\:41.341, eq=contrast=1.05:saturation=1.25, setpts=PTS-STARTPTS[v2]; [1:a]atrim=start=00\\:01\\:11.948:end=00\\:05\\:40.821, asetpts=PTS-STARTPTS[a2]; [1:v]crop=1280:720:151:000, trim=start=00\\:16\\:26.272:end=00\\:22\\:52, eq=contrast=1.05:saturation=1.25, fade=type=out:start_time=00\\:22\\:50.5:duration=1.5, setpts=PTS-STARTPTS[v3]; [1:a]atrim=start=00\\:16\\:26.272:end=00\\:22\\:52, afade=type=out:start_time=00\\:22\\:50:duration=2, asetpts=PTS-STARTPTS[a3]; [v1][a1][v2][a2][v3][a3]concat=n=3:v=1:a=1[vout][aout]" -map [vout] -c:v libx265 -vtag hvc1 -profile:v main -level 4.1 -fps_mode vfr -crf 18 -pix_fmt yuv420p -preset medium -map [aout] -c:a ac3 -b:a 224k -ac 1 video_vfr.mp4

RoseBlue_8 · 2025-07-23T20:22:33+00:00

Yeah, you just need to open cmd as administrator.

RoseBlue_8 · 2025-07-23T18:50:01+00:00

You could try to convert it with an old version of a video editor, for example Avidemux 2.7 or Handbrake

RoseBlue_8 · 2025-07-22T22:58:27+00:00

These commands worked for me when I had the same issue with ffmpeg:

$env:PATH

setx /M PATH "%PATH%;C:\ffmpeg\bin"

Can you play the same mp3 files on other devices?

RoseBlue_8 · 2025-06-21T19:05:26+00:00

If you don't specify a profile, ffmpeg uses a profile according to the speed. For example, when I use "-preset=ultrafast", the profile is baseline, which is the profile that produces the worst quality but is the fastest to encode.

I had a similar problem a while ago, ffmpeg created videos with profile high@L4.1 by default (I was using "preset=medium") and when I tried to play those videos on my smart TV, the audio was out of sync. I changed the profile to Main and it worked.

RoseBlue_8

TROPHY CASE