video-encoding interview questions
Top video-encoding frequently asked interview questions
I paid $59.95 for Vimeo Plus only to find that there is a 1 Gigabyte limit on video size.
I have a 4 GB MP4 video file that I shot with the HD Flip Mino. How do I reduce it to no more than 1 GIG without losing too much quality?
Source: (StackOverflow)
I have a digital camera that records nice 1080p H.264 format but unfortunately it uses the MOV container format. Basically I have nothing but the camera and VLC that play this format natively.
Is there a tool out there to convert the video to a format by just replacing the container format? That'd be a lot faster as the encoding is perfectly fine.
It'd be nice to select the folder and convert everything over to a more respectable container format like MP4.
I don't want to touch the actual quality of the video I want the conversion to be as fast as possible.
Source: (StackOverflow)
I want to compress an AVI file to MP4 using an h.264 codec. I could not get the same quality. How can I compress it?
Original Video:
Original Video Screen:
FFmpeg console output (ffmpeg -i input.avi):
FFmpeg version SVN-r26402, Copyright (c) 2000-2011 the FFmpeg developers
built on Dec 28 2012 10:03:40 with gcc 4.4.6 20120305 (Red Hat 4.4.6-4)
configuration: --enable-shared --enable-gpl --enable-version3 --enable-nonfree --enable-pthreads --enable-x11grab --enable-libopencore-amrnb --enable-libopenc ore-amrwb --enable-libdc1394 --enable-libfaac --enable-libmp3lame --enable-libop enjpeg --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-zlib --enable-filter=drawtext
libavutil 50.36. 0 / 50.36. 0
libavcore 0.16. 1 / 0.16. 1
libavcodec 52.108. 0 / 52.108. 0
libavformat 52.93. 0 / 52.93. 0
libavdevice 52. 2. 3 / 52. 2. 3
libavfilter 1.74. 0 / 1.74. 0
libswscale 0.12. 0 / 0.12. 0
[mpeg4 @ 0x626b50] Invalid and inefficient vfw-avi packed B frames detected
Input #0, avi, from 'input.avi':
Metadata:
encoder : VirtualDubMod 1.5.10.2 (build 2542/release)
Duration: 01:32:38.13, start: 0.000000, bitrate: 2094 kb/s
Stream #0.0: Video: mpeg4, yuv420p, 720x304 [PAR 1:1 DAR 45:19], 23.98 tbr, 23.98 tbn, 23.98 tbc
Stream #0.1: Audio: ac3, 44100 Hz, 5.1, s16, 384 kb/s
At least one output file must be specified
Test 1
FFmpeg command:
ffmpeg -i input.avi -vcodec libx264 -vpre lossless_slow -crf 25 -acodec libfaac -threads 0 -t 60 1.mp4
Test 1 Screen:
FFmpeg console output (ffmpeg -i 1.mp4)
FFmpeg version SVN-r26402, Copyright (c) 2000-2011 the FFmpeg developers
built on Dec 28 2012 10:03:40 with gcc 4.4.6 20120305 (Red Hat 4.4.6-4)
configuration: --enable-shared --enable-gpl --enable-version3 --enable-nonfree --enable-pthreads --enable-x11grab --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libdc1394 --enable-libfaac --enable-libmp3lame --enable-libopenjpeg --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-zlib --enable-filter=drawtext
libavutil 50.36. 0 / 50.36. 0
libavcore 0.16. 1 / 0.16. 1
libavcodec 52.108. 0 / 52.108. 0
libavformat 52.93. 0 / 52.93. 0
libavdevice 52. 2. 3 / 52. 2. 3
libavfilter 1.74. 0 / 1.74. 0
libswscale 0.12. 0 / 0.12. 0
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '1.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
creation_time : 1970-01-01 00:00:00
encoder : Lavf52.93.0
Duration: 00:01:00.01, start: 0.000000, bitrate: 618 kb/s
Stream #0.0(und): Video: h264, yuv420p, 720x304 [PAR 1:1 DAR 45:19], 437 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc
Metadata:
creation_time : 1970-01-01 00:00:00
Stream #0.1(und): Audio: aac, 44100 Hz, 5.1, s16, 176 kb/s
Metadata:
creation_time : 1970-01-01 00:00:00
At least one output file must be specified
Test 2
FFmpeg command:
ffmpeg -y -i input.avi -pass 1 -vcodec libx264 -vpre slow -b 2000k -threads 0 -t 60 -f mp4 -an -y /dev/null
ffmpeg -y -i input.avi -pass 2 -vcodec libx264 -vpre slow -b 2000k -threads 0 -t 60 -acodec libfaac -ab 128k -ac 2 2.mp4
Test 2 Screen:
FFmpeg console output (ffmpeg -i 2.mp4)
FFmpeg version SVN-r26402, Copyright (c) 2000-2011 the FFmpeg developers
built on Dec 28 2012 10:03:40 with gcc 4.4.6 20120305 (Red Hat 4.4.6-4)
configuration: --enable-shared --enable-gpl --enable-version3 --enable-nonfree --enable-pthreads --enable-x11grab --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libdc1394 --enable-libfaac --enable-libmp3lame --enable-libopenjpeg --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-zlib --enable-filter=drawtext
libavutil 50.36. 0 / 50.36. 0
libavcore 0.16. 1 / 0.16. 1
libavcodec 52.108. 0 / 52.108. 0
libavformat 52.93. 0 / 52.93. 0
libavdevice 52. 2. 3 / 52. 2. 3
libavfilter 1.74. 0 / 1.74. 0
libswscale 0.12. 0 / 0.12. 0
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '2.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
creation_time : 1970-01-01 00:00:00
encoder : Lavf52.93.0
Duration: 00:01:00.01, start: 0.000000, bitrate: 1097 kb/s
Stream #0.0(und): Video: h264, yuv420p, 720x304 [PAR 1:1 DAR 45:19], 1028 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc
Metadata:
creation_time : 1970-01-01 00:00:00
Stream #0.1(und): Audio: aac, 44100 Hz, stereo, s16, 63 kb/s
Metadata:
creation_time : 1970-01-01 00:00:00
At least one output file must be specified
Source: (StackOverflow)
I would like to archive some home videos (DV). I don't need to save them losslessly, but I would like to encode them in something high-quality.
What format is both pretty indistinguishable from the original and will likely be readable 15 years from now?
WMA makes me nervous, because it's only one company that makes it, and they're constantly coming out with newer formats. (VLC couldn't open my WMAs that Windows Movie Maker made.)
Other things I've considered are h.264, Ogg Theora, DivX, and Xvid.
I don't mind paying for something, but usually that means the format is owned by only one vendor.
Source: (StackOverflow)
Release group LOL does an excellent job at encoding their releases on The Vampire Diaries (on other shows like How I Met Your Mother the bitrate is higher, so doesn't seem this effective).
About 200 MB each ~45mins MP4 file, amazing quality considering.
I just wonder what settings and what software they use. I've tried to get info from these files using MediaInfo, then use the settings in HandBrake, but I didn't really succeed.
Could anyone please help me? I don't have much knowledge about encoding/compressing.
Source: (StackOverflow)
I'm using VirtualDub for encoding with those settings.
However I record my stuff in 1920x1080 and resize it down to 1280x720. Now the question: which algorithm should I choose when making a balanced quality vs. file-size decision?
I always went with Lanczos because that's what was pre-configured. Those descriptions don't really help me at all in my question.
Source: (StackOverflow)
I'm trying to encode an image-sequence (frame0001.png, frame0002.png, ... , frame0160.png) into an x264 video using the following command:
ffmpeg -i frame%04d.png -sameq -r 24 out.mp4
After encoding, it says drop=5 and indeed there are noticeable “jumps” in the video.
It appears someone else had a similar problem, but for me the accepted answer isn't very useful since I'd like to have no frames dropped.
Is a switch missing from the command? Or am I doing something else wrong?
Edit: Added console output:
ffmpeg version N-42347-g299387e Copyright (c) 2000-2012 the FFmpeg developers
built on Jul 8 2012 15:46:39 with gcc 4.7.1
configuration: --disable-static --enable-shared --enable-gpl --enable-version3
--disable-w32threads --enable-runtime-cpudetect --enable-avisynth --enable-bzli
b --enable-frei0r --enable-libass --enable-libcelt --enable-libopencore-amrnb --
enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --enable-libmp3lam
e --enable-libnut --enable-libopenjpeg --enable-librtmp --enable-libschroedinger
--enable-libspeex --enable-libtheora --enable-libutvideo --enable-libvo-aacenc
--enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --en
able-libxavs --enable-libxvid --enable-zlib
libavutil 51. 64.100 / 51. 64.100
libavcodec 54. 33.100 / 54. 33.100
libavformat 54. 15.102 / 54. 15.102
libavdevice 54. 1.100 / 54. 1.100
libavfilter 3. 1.100 / 3. 1.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
Input #0, image2, from 'frame%04d.png':
Duration: 00:00:06.40, start: 0.000000, bitrate: N/A
Stream #0:0: Video: png, rgb24, 1920x1080, 25 fps, 25 tbr, 25 tbn, 25 tbc
[graph 0 input from stream 0:0 @ 01cd1f60] w:1920 h:1080 pixfmt:rgb24 tb:1/25 fr
:25/1 sar:0/1 sws_param:flags=2
[output stream 0:0 @ 01cd2220] No opaque field provided
[auto-inserted scaler 0 @ 01cd3540] w:1920 h:1080 fmt:rgb24 sar:0/1 -> w:1920 h:
1080 fmt:yuv420p sar:0/1 flags:0x4
[libx264 @ 01cd0dc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 Cache64
[libx264 @ 01cd0dc0] profile High, level 4.0
[libx264 @ 01cd0dc0] 264 - core 125 r2200 999b753 - H.264/MPEG-4 AVC codec - Cop
yleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deb
lock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 m
e_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chro
ma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 i
nterlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1
b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=24 scenec
ut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=
0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'out.mp4':
Metadata:
encoder : Lavf54.15.102
Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 1920x1080, q=-1-
-1, 24 tbn, 24 tbc
Stream mapping:
Stream #0:0 -> #0:0 (png -> libx264)
Press [q] to stop, [?] for help
frame= 8 fps=0.0 q=0.0 size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
frame= 15 fps= 15 q=0.0 size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
frame= 22 fps= 14 q=0.0 size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
frame= 29 fps= 14 q=0.0 size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
frame= 36 fps= 14 q=0.0 size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
frame= 43 fps= 14 q=0.0 size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
frame= 47 fps= 11 q=0.0 size= 0kB time=00:00:00.00 bitrate= 0.0kbits/s
frame= 53 fps= 11 q=28.0 size= 111kB time=00:00:00.04 bitrate=21735.2kbits
frame= 59 fps= 11 q=28.0 size= 268kB time=00:00:00.29 bitrate=7527.8kbits/
frame= 63 fps= 10 q=28.0 size= 375kB time=00:00:00.45 bitrate=6708.1kbits/
frame= 69 fps= 10 q=28.0 size= 538kB time=00:00:00.70 bitrate=6219.6kbits/
frame= 74 fps= 10 q=28.0 size= 675kB time=00:00:00.91 bitrate=6032.7kbits/
frame= 79 fps= 10 q=28.0 size= 802kB time=00:00:01.12 bitrate=5840.7kbits/
frame= 84 fps= 10 q=28.0 size= 922kB time=00:00:01.33 bitrate=5662.9kbits/
frame= 89 fps=9.9 q=28.0 size= 1060kB time=00:00:01.54 bitrate=5633.3kbits/
frame= 94 fps=9.9 q=28.0 size= 1186kB time=00:00:01.75 bitrate=5551.2kbits/
frame= 98 fps=9.7 q=28.0 size= 1309kB time=00:00:01.91 bitrate=5594.3kbits/
frame= 103 fps=9.7 q=28.0 size= 1436kB time=00:00:02.12 bitrate=5536.4kbits/
frame= 107 fps=9.6 q=28.0 size= 1533kB time=00:00:02.29 bitrate=5481.7kbits/
frame= 112 fps=9.5 q=28.0 size= 1654kB time=00:00:02.50 bitrate=5421.3kbits/
frame= 117 fps=9.4 q=28.0 size= 1781kB time=00:00:02.70 bitrate=5386.9kbits/
frame= 123 fps=9.4 q=28.0 size= 1925kB time=00:00:02.95 bitrate=5331.5kbits/
frame= 128 fps=9.4 q=28.0 size= 2030kB time=00:00:03.16 bitrate=5250.8kbits/
frame= 133 fps=9.4 q=28.0 size= 2210kB time=00:00:03.37 bitrate=5363.8kbits/
frame= 138 fps=9.3 q=28.0 size= 2356kB time=00:00:03.58 bitrate=5386.0kbits/
frame= 142 fps=9.3 q=28.0 size= 2465kB time=00:00:03.75 bitrate=5384.3kbits/
frame= 147 fps=9.3 q=28.0 size= 2602kB time=00:00:03.95 bitrate=5385.0kbits/
frame= 151 fps=9.2 q=28.0 size= 2706kB time=00:00:04.12 bitrate=5374.3kbits/
frame= 155 fps=9.2 q=28.0 size= 2812kB time=00:00:04.29 bitrate=5367.7kbits/
frame= 155 fps=7.0 q=28.0 Lsize= 4129kB time=00:00:06.37 bitrate=5306.4kbits
/s dup=0 drop=5
video:4128kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.035320%
[libx264 @ 01cd0dc0] frame I:2 Avg QP:21.97 size: 79850
[libx264 @ 01cd0dc0] frame P:153 Avg QP:23.43 size: 26579
[libx264 @ 01cd0dc0] mb I I16..4: 9.6% 70.5% 19.9%
[libx264 @ 01cd0dc0] mb P I16..4: 7.0% 15.3% 0.7% P16..4: 45.2% 9.1% 2.2%
0.0% 0.0% skip:20.5%
[libx264 @ 01cd0dc0] 8x8 transform intra:66.7% inter:85.7%
[libx264 @ 01cd0dc0] coded y,uvDC,uvAC intra: 38.6% 58.0% 6.0% inter: 16.2% 27.2
% 0.2%
[libx264 @ 01cd0dc0] i16 v,h,dc,p: 35% 29% 17% 19%
[libx264 @ 01cd0dc0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 21% 31% 3% 4% 5% 4%
4% 3%
[libx264 @ 01cd0dc0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 19% 13% 5% 8% 9% 7%
6% 4%
[libx264 @ 01cd0dc0] i8c dc,h,v,p: 49% 23% 23% 5%
[libx264 @ 01cd0dc0] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 01cd0dc0] ref P L0: 84.5% 10.9% 3.5% 1.1%
[libx264 @ 01cd0dc0] kb/s:5235.14
Source: (StackOverflow)
What tool can I use to to rip DVD movies? I have used "Dr. DivX" long back. Is there any better tool to rip DVDs?
Source: (StackOverflow)
I want to encode a video file to H.265. The last version of ffmpeg should be support H.265 (Source).
However, I could not find any information about the exact command.
I do not know, which library I should indicate after -vcodec.
I use the lastest Zeranoe FFmpeg Build (git-c78a416 (2013-10-26)).
Source: (StackOverflow)
I am so confused.
I am trying a quite simple FFMpeg command to transcode a movie file to a x264/AAC mp4 file via the command line (for Vimeo upload). (Mountain Lion/Macports)
ffmpeg -i INPUT.AVI -vcodec libx264 -acodec libfaac -preset hq -s hd720 -b 5000k -ar 44100 -ab 320k OUTPUT.mp4
Problem: FFMpeg cannot find the libfaac library. I have read it has recently been taken out. True? I also have read that I better use NeroAACEnc or libvo_aacenc anyways as they might be better quality-wise.
How do I:
- Add
NeroAACEnc and/or libvo_aacenc to my system?
- What is the correct command line to invoke one of these when they are installed? I have seen solutions with pipes etc.
Command line, Linux and Unix work is all a bit new to me, so I cannot work out what internet is telling me to do. Macports confuses me a bit too.
Looking forward to your pro help here.
Here is the complete iTerm2 output:
ffmpeg -i test.mp4 -vcodec libx264 -acodec libfaac -preset hq -s hd720 -b 5000k -ar 44100 -ab 320k OUTPUT.mp4
ffmpeg version 0.11.1.git Copyright (c) 2000-2012 the FFmpeg developers
built on Aug 4 2012 11:25:44 with clang 4.0 ((tags/Apple/clang-421.0.57))
configuration: --prefix=/opt/local --enable-swscale --enable-avfilter --enable-libmp3lame --enable-libvorbis --enable-libtheora --enable-libschroedinger --enable-libopenjpeg --enable-libmodplug --enable-libvpx --enable-libspeex --mandir=/opt/local/share/man --enable-shared --enable-pthreads --cc=/usr/bin/clang --enable-gpl --enable-postproc --enable-libx264 --enable-libxvid --arch=x86_64 --enable-yasm
libavutil 51. 65.100 / 51. 65.100
libavcodec 54. 41.100 / 54. 41.100
libavformat 54. 17.100 / 54. 17.100
libavdevice 54. 1.100 / 54. 1.100
libavfilter 3. 2.100 / 3. 2.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42isomavc1
creation_time : 2012-04-27 12:10:05
encoder : HandBrake 0.9.6 2012022800
Duration: 00:00:32.83, start: 0.000000, bitrate: 3241 kb/s
Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 3074 kb/s, 29.97 fps, 30 tbr, 90k tbn, 180k tbc
Metadata:
creation_time : 2012-04-27 12:10:05
Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, s16, 164 kb/s
Metadata:
creation_time : 2012-04-27 12:10:05
Please use -b:a or -b:v, -b is ambiguous
Unknown encoder 'libfaac'
Source: (StackOverflow)
I have a bunch of commandline settings that work for handbrake, but sometimes on some videos (I have no idea why) handbrake throws "Out of memory exception". I was wondering if I can find the same option keys and do it with FFmpeg, but it seems not so easy thing to do.
FFmpeg sometimes either doesn't have those options or does stuff by default. For example I don't know how to do custom anamorphic with FFmpeg. For me very is important that resulting videos will be as good as if they're done with handbrake. Here's the line for Handbrake:
HandBrakeCLI.exe --input "d:\input.mpg" --output "d:\output.mp4" --rate 29.97 --cfr --arate 44.1 --format mp4 --width 1920 --height 1080 --custom-anamorphic --display-width 1920 --keep-display-aspect --modulus 8 --crop 0:0:0:0 --encoder x264 --vb 5200 --aencoder faac --ab 128 --mixdown stereo -x bitrate=5200:vbv-bufsize=5200:vbv-maxrate=5200:level=42:bframes=2:min-keyint=60:keyint=60:ref=4:me=umh:merange=64:subme=7:8x8dct:cabac=1 -v3 -2 -a none
How do I turn this to an FFmpeg command?
Source: (StackOverflow)
I have a promotional DVD from a client, and they want to put clips from it on their website.
I'm in a Windows environment, so I'm looking for a decent video editor program, free would be preferred. Then I guess I'd have some kind of flash-based player to embed in the website...
What do you recommend?
Source: (StackOverflow)
Handbrake is an awesome video compression tool, but it doesn't seem to preserve the original capture time after a video is compressed. Any idea how to fix this?
Source: (StackOverflow)
I recently got a helmet camera for my motorbike and was able to make videos, however it stores it in Motion JPEG, which is very space inefficent. 30 minutes of 640x480 takes up 2GB. I can convert that to mpg, with this command:
ffmpeg -i myvideo.avi myvideo.mpg
Which is a good space saving. However is this the best video format? Should I use something new like AAC? If so, how? (ie what's the ffmpeg/mencoder/gstreamer/transcode command)
Requirements:
- Convertable on linux using only open source tools
- Must play on linux
- Don't care about making it play on other devices (like ipods)
- Should keep reasonably the same quality
- Don't care about the audio, I'm tempted to remove it
- I'm willing to use 'patent encumbered' formats like mp3, etc.
- I'm not too interested in shaving miliseconds off treanscoding time or extreme file savings.
Source: (StackOverflow)
I would like to know the best (fast) software for video encoding and transcoding video into h.264 that makes use of Intel Quick Sync.
I looked at Media Espresso by Cyberlink but it does not have many features. I can't even put a logo on the video using this. Just that one feature would really help.
But nothing else even comes close to the speed of encoding with my i7 2600k.
Source: (StackOverflow)