conversion interview questions
Top conversion frequently asked interview questions
I have a woff file I downloaded from a website that I want to convert for use in word documents and such.
Is there any (free) way to do this?
After much searching I have not found a way, so I am turning to superuser for help.
Source: (StackOverflow)
Someone sent me a bunch of BMP files and I need them in JPEG. I could convert them one by one using GIMP, but I'd rather do it all in one go. I have Ubuntu.
Source: (StackOverflow)
How would you convert (decode) AAC files into WAV format? (Or, if you prefer, how to decode & re-encode them into MP3 or Ogg Vorbis? But WAV is sufficient as I already have good tools for WAV ➔ MP3/Ogg conversion.)
I'm mostly interested in Mac or Linux solutions, but feel free to mention Windows ones too.
(Use case: I have some voice memos ("Apple lossless audio file"), recorded with iPhone, that I'd like to share in a format that's more common than AAC.)
Source: (StackOverflow)
I have a set of files in .doc format, that need to be converted to .pdf format. I am using Ubuntu linux.
Source: (StackOverflow)
I have a 500GB external hard disk which I use mostly for storing movies/music and some backup. Since I have some rather large files I use NTFS on it, but don't need the security/compression/encryption features. I recently read about exFAT and as far as I understand it solves my shortcomings of FAT32, so decided to give exFAT a try.
Can anyone suggest an utility to convert my existing NTFS volume to exFAT (or vice versa) without losing contents?
Source: (StackOverflow)
What software exists can do this conversion?
I work with some software that can't handle newer PDFs made with Adobe Acrobat 9 Pro and other newer office programs.
Price and platform doesn't matter as long as it's not too expensive.
Source: (StackOverflow)
I got a PRN file but I would to convert to PDF so that it will be easier for other people to access. How do I do that?
Source: (StackOverflow)
Can Apple Lossless audio files (ALAC) be converted to FLAC audio files with no loss of fidelity?
Source: (StackOverflow)
To convert an MKV to AVI, I do two things. The first thing I do is this:
ffmpeg -i filename.mkv -vcodec copy -acodec copy output.avi
or this:
ffmpeg -i filename.mkv -sameq -acodec copy output.avi
Either of these will convert the MKV to an AVI, but the problem is that the video does not play smoothly for some reason. That's fine though, because if I do one more thing it gets fixed:
ffmpeg -i output.avi -vcodec mpeg4 -b 4000k -acodec mp2 -ab 320k converted.avi
After I do this then the file plays without problem. I had success doing it this way for one file, but then I tried it on another file, and there is a slight, but noticeable loss in video quality. This is the output I get when doing the second step:
FFmpeg version 0.6.1, Copyright (c) 2000-2010 the FFmpeg developers
built on Dec 29 2010 18:02:10 with gcc 4.2.1 (Apple Inc. build 5664)
configuration:
libavutil 50.15. 1 / 50.15. 1
libavcodec 52.72. 2 / 52.72. 2
libavformat 52.64. 2 / 52.64. 2
libavdevice 52. 2. 0 / 52. 2. 0
libswscale 0.11. 0 / 0.11. 0
Seems stream 0 codec frame rate differs from container frame rate: 359.00 (359/1) -> 29.92 (359/12)
Input #0, avi, from 'output.avi':
Metadata:
ISFT : Lavf52.64.2
Duration: 00:04:17.21, start: 0.000000, bitrate: 3074 kb/s
Stream #0.0: Video: mpeg4, yuv420p, 704x480 [PAR 229:189 DAR 5038:2835], 29.92 fps, 29.92 tbr, 29.92 tbn, 359 tbc
Stream #0.1: Audio: vorbis, 48000 Hz, stereo, s16
Output #0, avi, to 'converted.avi':
Metadata:
ISFT : Lavf52.64.2
Stream #0.0: Video: mpeg4, yuv420p, 704x480 [PAR 229:189 DAR 5038:2835], q=2-31, 4000 kb/s, 29.92 tbn, 29.92 tbc
Stream #0.1: Audio: mp2, 48000 Hz, stereo, s16, 320 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #0.1 -> #0.1
I just used arbitrarily large settings on the second step and it worked nicely before but not in this case. What settings should I use?
Source: (StackOverflow)
My son has made some animations with Pivot Stickfigure Animator which we'd like to upload to YouTube. The problem is Pivot saves as animated GIFs which I can't upload to YouTube.
The Wikipedia article recommends using Windows Movie Maker to convert GIF to WMV, but unfortunately I'm using Windows 7 for which you can get the new Windows Live Movie Maker which doesn't seem to support GIFs.
I Googled and found an article which said to use Beneton Movie GIF to convert animated GIF to AVI, but this seemed to rely on a 3rd Party application which wasn't installed and so failed. Installing the missing application - pjBmp2Avi - by hand and adding it to the path still didn't allow Beneton to do the conversion.
I hoped FFmpeg might do the trick but this only outputs to animated GIFs, it won't read from then.
Further Googling found lots of applications with 30 day trials and so on but I was hoping for something free.
So any suggestions on how I can convert an animated GIF to a movie file on Windows using free (as in beer) software?
Source: (StackOverflow)
When a certain file (mp4, flv, etc) has a 95 kbps audio bitrate - does it make sense outputing to a higher bitrate when converting to mp3 or other format (be it lossy or not)?
Would this result in higher audio quality or just in a bigger file?
Edits after a lot of answers+comments:
I am not talking about the output having better quality than the input: obviously, that is not possible. (Except for going from a lossless format to the original wave.) I am talking whether an output with a higher bitrate than the input will have a better quality than it might otherwise have.
please consider that I am aware that converting between lossy formats is not recommendable. Only that in some cases an original cd/wave may be unavailable. The question is just about the usefulness of optionally increasing the bitrate when converting.
maybe a sub-question is useful: is the answer dependent on the type of the output file (lossless or lossy)?
the most voted two answers below (this and this) seem to say different things, namely, the later says that Bitrates are not directly comparable and if the original audio is in a more efficient format, then the output (less efficient) audio should have a somewhat superior bitrate (the same idea here and here) - but while the less efficient is mp3, I am not sure which exactly are the more efficient formats. (is it aac?) (-- And in general the answers seem to fall in one of the two positions represented by the most voted answers.)
Source: (StackOverflow)
I'm trying to convert a .mov to a .gif and I'm not having success.
Here's the error:
ffmpeg -pix_fmt rgb24 -i yesbuddy.mov output.gif
ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers
built on Jun 12 2012 17:47:34 with clang 2.1 (tags/Apple/clang-163.7.1)
configuration: --prefix=/usr/local/Cellar/ffmpeg/0.11.1 --enable-shared --enable-gpl --enable-version3 --enable-nonfree --enable-hardcoded-tables --enable-libfreetype --cc=/usr/bin/clang --enable-libx264 --enable-libfaac --enable-libmp3lame --enable-librtmp --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libass --enable-libvo-aacenc --disable-ffplay
libavutil 51. 54.100 / 51. 54.100
libavcodec 54. 23.100 / 54. 23.100
libavformat 54. 6.100 / 54. 6.100
libavdevice 54. 0.100 / 54. 0.100
libavfilter 2. 77.100 / 2. 77.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
Option pixel_format not found.
If I leave out the -pix_fmt rgb24 part it complains. Thoughts on how to fix?
Source: (StackOverflow)
I've the following PDF file:
http://www.fmwconcepts.com/misc_tests/pdf_tests/test.pdf
But when I'm trying to convert it via:
$ convert test.pdf test.png
I've the following error:
convert: no images defined `test.png' @ error/convert.c/ConvertImageCommand/3187.
I've the following versions:
$ brew info libpng
libpng: stable 1.6.13 (bottled)
$ brew info libjpeg
jpeg: stable 8d (bottled)
$ brew info imagemagick
imagemagick: stable 6.8.9-7 (bottled), HEAD
http://www.imagemagick.org
/usr/local/Cellar/imagemagick/6.8.9-1 (1432 files, 22M) *
Poured from bottle
From: https://github.com/Homebrew/homebrew/blob/master/Library/Formula/imagemagick.rb
==> Dependencies
Build: xz ✔, pkg-config ✔
Required: libtool ✔
Recommended: jpeg ✔, libpng ✔, freetype ✔
Optional: fontconfig ✔, libtiff ✔, little-cms ✔, little-cms2 ✔, libwmf ✘, librsvg ✘, liblqr ✘, openexr ✘, ghostscript ✘, webp ✘
I've the following debug log:
$ convert test.pdf test.png -debug all
2014-10-01T15:29:39+01:00 0:00.000 0.000u 6.8.9 Configure convert[58320]: utility.c/ExpandFilenames/944/Configure
Command line: convert {test.pdf} {test.png} {-debug} {all}
2014-10-01T15:29:39+01:00 0:00.000 0.000u 6.8.9 Configure convert[58320]: configure.c/GetConfigureOptions/679/Configure
Searching for configure file: "/usr/local/Cellar/imagemagick/6.8.9-1/share/ImageMagick-6/coder.xml"
...
2014-10-01T15:29:39+01:00 0:00.020 0.010u 6.8.9 Module convert[58320]: module.c/OpenModule/1268/Module
Searching for module "PNG" using filename "png.la"
2014-10-01T15:29:39+01:00 0:00.020 0.010u 6.8.9 Module convert[58320]: module.c/GetMagickModulePath/554/Module
Searching for coder module file "png.la" ...
2014-10-01T15:29:39+01:00 0:00.020 0.010u 6.8.9 Module convert[58320]: module.c/OpenModule/1277/Module
Opening module at path "/usr/local/Cellar/imagemagick/6.8.9-1/lib/ImageMagick//modules-Q16/coders/png.la"
2014-10-01T15:29:39+01:00 0:00.020 0.010u 6.8.9 Module convert[58320]: module.c/OpenModule/1304/Module
Method "RegisterPNGImage" in module "PNG" at address 0x10a9fdb60
2014-10-01T15:29:39+01:00 0:00.020 0.010u 6.8.9 Module convert[58320]: module.c/OpenModule/1318/Module
Method "UnregisterPNGImage" in module "PNG" at address 0x10aa0785d
2014-10-01T15:29:39+01:00 0:00.020 0.010u 6.8.9 Policy convert[58320]: policy.c/IsRightsAuthorized/574/Policy
Domain: Path; rights=Read; pattern="test.png" ...
...
2014-10-01T15:29:39+01:00 0:00.020 0.010u 6.8.9 Configure convert[58320]: locale.c/LoadLocaleCache/1186/Configure
Loading locale configure file "/usr/local/Cellar/imagemagick/6.8.9-1/share/ImageMagick-6/english.xml" ...
2014-10-01T15:29:39+01:00 0:00.020 0.020u 6.8.9 Exception convert[58320]: blob.c/OpenBlob/2657/Exception
unable to open image `test.png': No such file or directory
2014-10-01T15:29:39+01:00 0:00.020 0.020u 6.8.9 Cache convert[58320]: cache.c/DestroyPixelCache/962/Cache
destroy
2014-10-01T15:29:39+01:00 0:00.020 0.020u 6.8.9 Policy convert[58320]: policy.c/IsRightsAuthorized/574/Policy
Domain: Coder; rights=Read; pattern="PNG" ...
2014-10-01T15:29:39+01:00 0:00.030 0.020u 6.8.9 Coder convert[58320]: png.c/ReadPNGImage/4015/Coder
Enter ReadPNGImage()
2014-10-01T15:29:39+01:00 0:00.030 0.020u 6.8.9 Policy convert[58320]: policy.c/IsRightsAuthorized/574/Policy
Domain: Path; rights=Read; pattern="test.png" ...
2014-10-01T15:29:39+01:00 0:00.030 0.020u 6.8.9 Exception convert[58320]: blob.c/OpenBlob/2657/Exception
unable to open image `test.png': No such file or directory
2014-10-01T15:29:39+01:00 0:00.030 0.020u 6.8.9 Exception convert[58320]: png.c/ReadPNGImage/4021/Exception
unable to open file `test.png'
But doesn't showing anything obvious. And it seems that this debug log behaves completely different than without -debug, because the original error is not there. See the full log.
There is a similar issue at http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=22466, but I'm not quite get it what is the solution.
Source: (StackOverflow)