34
votes
Accepted
How to downsample 4k to 1080p using ffmpeg while maintaining the quality?
The default settings for ffmpeg are very low quality, and since you don't specify any codec or quality parameters it's just using the defaults (I don't know why the devs don't fix that because it ...
- 13.4k
28
votes
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Can I set the start number for image sequence output?
The image sequence muxer has a start number option, so
ffmpeg -i video.webm -start_number 98 image-%03d.png
- 30.2k
12
votes
Accepted
Big difference in the video file size after the conversion (.mov to .mp4)
Let me explain you from scratch.
MOV, MP4, AVI, MKV etc all these are just containers, It is just kind of wrapper which contains audio, video, text, metadata file together as one file. It does not ...
- 181
8
votes
Accepted
Video converted by FFMPEG has a different duration, why?
Hope this explanation is what you're looking for:
When you transcode to an encoding such as H.264 (MPEG-4 part 10) you necessarily also resample the video, that's part of H.264 compression technique. ...
- 486
8
votes
Accepted
Does transcoding always mean quality loss?
Generally, H.264 and H.265 (as well as others like VP9) are lossy codecs, at least in their default settings with most encoders. This means that whenever you re-encode from one to another (or even in ...
- 955
7
votes
Accepted
Apply custom lut via ffmpeg?
You may want to use FFMPEG's lut3d filter. It requires you to provide a look-up table (a *.cube file). For example, if you have an ARRI camera you can generate these files using ARRI Color Tool or ...
- 423
6
votes
Accepted
Converting video with different resolutions slightly affects in file size, why?
You are using the same bitrate for each video. The bitrate determines how much data is used per second. The resolution has nothing to do with how much data is used, it only impacts the number of ...
- 19.2k
6
votes
Accepted
FFMPEG convert video with multiple audio streams?
If you copied your command there then your issue is probably -acodec:0 mp. That should be -acodec:0 mp3.
You can just use -c:a mp3 to apply the encoding options to all audio tracks at once, no need ...
- 7,099
6
votes
Accepted
FFMPEG stop converting from TrueHD to PCM
The WAV header is typically 32-bits. Your output will need 64 bits.
ffmpeg -i source.thd -c:a pcm_s24le -ar 48000 -rf64 auto output.wav
- 30.2k
6
votes
Accepted
Convert video with ffmpeg to have the same quality
The differences between your "works" and "doesn't work" examples are:
resolution
framerate
Codec Tag
Codec Level
and you can set these using ffmpeg:
ffmpeg.exe -i /temp/input.mp4 -c:v mpeg4 -level ...
- 176
5
votes
Quality of VHS converted to DVD
One big loss in converting VHS to DVD arises from going through the composite domain. Both VHS and MPEG2 use a separated chroma paradigm -- on the VHS tape are two signals, essentially luma and ...
- 4,654
5
votes
Accepted
Loss of quality while adding subtitle via FFmpeg
As you are hardcoding subtitles, the video (with the subtitles added) will be re-encoded.
You can use the CRF rate control method to modulate the quality of the output.
So, start with
ffmpeg -i ...
- 30.2k
5
votes
Accepted
Problem converting TS to MP4 container with ffmpeg
Update: The VLC TS is malformed.
First run
ffmpeg -i vlc-output.ts -c copy ffmpeg-output.ts
and then
ffmpeg -i ffmpeg-output.ts -c copy working.mp4
The main thing that looks off is the timebase ...
- 30.2k
5
votes
Easily convert & archive a bunch of low res Video CD DAT files MPEG 1/2 to newer better format such as MKV or others?
Using ffmpeg, a free command-line tool, you can convert these DATs to MP4 (or MKV):
ffmpeg -i input.dat -c:v libx264 -crf 20 -c:a aac -b:a 128k -movflags +faststart output.mp4
Your VLC output doesn'...
- 30.2k
4
votes
How to digitise old NTSC home videos for highest quality (with PAL player)?
As far as deinterlacing: With a good deinterlacer (QTGMC, or at least ffmpeg's yadif=3,mcdeint=2), you can get smooth video at 60000/1001 (NTSC) fps. If your source has quick motions that you'd like ...
- 2,618
4
votes
How can I efficiently convert MOV / MPEG-4 files for long term storage?
Although @stib's advice is sound, I disagree with "to get an appreciable size reduction you would have to throw away a lot of quality". Cameras have to compress on-the-fly, so they use constrained ...
- 30.2k
4
votes
Accepted
mplayer/ffmpeg How to set caca filter's output size
Found. Caca library is driven mostly by environment variables rather than filter params.
export CACA_GEOMETRY=200x78
mplayer -vo caca $INPUT
- 179
4
votes
Accepted
ffmpeg to convert and merge 3 videos to a single widescreen video
Quality-wise, it's better to use the original MOVs, but if the MP4-based stacking looks ok, that's the final arbiter.
ffmpeg -i left.mov -i centre.mov -i right.mov
-filter_complex "[0:v:0][1:v:0][2:...
- 30.2k
4
votes
Accepted
Lossless convert 3gp video to mp4 using ffmpeg
If the codecs of your input file are already h264 and aac for video and audio, respectively, you can just copy without decoding and encoding again.
ffmpeg -i input.3gp -c:v copy -c:a copy output.mp4
...
- 176
3
votes
Converting from 3/4" video to digital.
Assuming DVD quality would be enough, you may consider archiving 720p mpeg-4 files with a bitrate of 2 Mbits, which would equate roughly to 1 hour = 1 GB data.
That would mean 27,000 hours = 27,000 ...
- 131
3
votes
How to convert a .m4v video/audio file to .mp4 on Windows-7, for free
Somewhat of an duplicate of: Can I manually change an .mp4 to .m4v by changing the extension in the Finder (mac) or explorer (win)?
MP4 and M4V are essentially the exact same thing, M4V is usually ...
- 7,099
3
votes
What is the most lossless way to rip a laserdisc to a Mac?
A lot of these answers seem somewhat misleading unfortunately.
Forget about getting a capture card. Practically every one has AGC. AGC is very similar to macrovision, except it's superimposed onto ...
- 31
3
votes
Accepted
How can I convert large jpgs (15000 x 10840px) to video?
That's way more than h.264 can handle. The maximum resolution for h.264 is 4096×2304 with Level 5.1 or 5.2.
http://en.wikipedia.org/wiki/H.264#Levels
There are lossless codecs who can theoretically ...
- 7,099
3
votes
Can video frame size be increased?
There are a few problems here that need to be addressed.
First, the pitch shot is vertically oriented or "portrait" (vs landscape). This is considered very, very bad practice. This is a huge and ...
- 19.2k
3
votes
How can I reduce the size of a webm to 2MB?
Use Avanti with ffmpeg. The former has a job control manager where you drop in multiple files at once and go. You can find webm encoding guide for ffmpeg here: http://trac.ffmpeg.org/wiki/Encode/VP8
...
- 30.2k
3
votes
Accepted
Why does VLC player convert a 4-minute mp4 to a 4-hour webm?
Yes, it seems to be a problem of generated timecode. See https://trac.videolan.org/vlc/ticket/12713#no1
Switch to ffmpeg (with a GUI like Avanti) to avoid this issue. My answer to an earlier webm ...
- 30.2k
3
votes
Accepted
Convert resolution 4096x2304 to 3840x2160 keeping the quality the same
Judge based on the quality rather than the bitrate value. Use CRF mode encoding and if the quality isn't what you can accept, decrease the CRF value.
ffmpeg -i "%%a" -s 3840x2610 -c:v libx264 -crf 18 ...
- 30.2k
3
votes
Accepted
convert horizontal side by side to vertically stacked 3D video
Just integrate all filtering into one command:
ffmpeg -i input.mp4 \
-filter_complex "[0:v]crop=in_w/2:in_h:0:0 [top]; \
[0:v]crop=in_w/2:in_h:in_w/2:0[bottom]; \
[top][bottom]vstack[outv]" \
-map "[...
- 30.2k
3
votes
Accepted
what graphics card features effect NVIDIA NVENC hardware encoding speed?
There are two main features in NVIDIA NVENC encoding:
Video memory if you need to transcode many streams.
NVENC SIP - than better this SIP than better encoding performance
is. It depends on GPU. You ...
- 391
3
votes
Accepted
Video format can't be played or converted
Use this ffmpeg* command:
ffmpeg -i "20151105-175532.dad" -c:v copy "20151105-175532.mp4"
*get 32-bit static build.
- 30.2k
Only top scored, non community-wiki answers of a minimum length are eligible