I can't find a way to download the worst audio file quality of a video using youtube-dl, people ask how to download the best quality (and short answer is it automatically downloads the best) but what if I want the worst?
using the -F option I get this output :
Of course I could just type -f 249 to manually choose the tiniest audio only file to download. But I am trying to make an automated system, to download the worst quality of any video, therefore I can't use this format (it may change).
I could use --audio-format webm but as you can see in the screenshot there are 3 candidates and again youtube-dl downloads the best of the three (the worst quality being the lowest in this webm format).
I could use --audio-quality 9 but this is a post-processing option which means it will first download the best quality and then converts it afterwards (not bandwidth-friendly, my last option....).
What is a proper way to download the worst quality? (lastly I tried -f worst -x but it doesn't work)
Edit : Also, I know that I can use the output of -F and slice the lines to determine the worst audio available. But I am probing if there is any way to directly do that using youtube-dl
Haven't tried yet, but, according to the docs, you can use:
wa, worstaudio: Select the worst quality audio-only format. Equivalent to worst*[vcodec=none]
Check the latest paragraphs on the "Sorting Formats" section of the docs for more info.
Related
First, thanks for any and all help regarding this topic.
Sites like Facebook and Twitter strip EXIF information from images as they are uploading. My goal is to allow users to upload images to our platform (working with Nextcloud and others) with full EXIF information, however, we need to display images that do not contain EXIF information or any metadata. Without stripping and creating a second, Exif-Free image for each, is it possible to simply hide that EXIF info so that, if a user downloads that image, the EXIF is not embedded?
We were told that the only way to do this is to have a second, exif-free copy (the order of when that's created is irrelevant pre/during/post upload). I'm hoping there's a way that we can simply display such a copy without doubling our physical space requirements.
Thanks again for your help.
Exif is metadata, along with IPTC, XMP, AFCP, ICC, FPXR, MPF, JPS and a comment, just for the JFIF/JPEG file format alone. Other picture file formats support even more/other metadata.
You wrote it yourself: a download - so it's a file in any case. Pictures are files, just like executables, movies, texts, music and archives are files, too. And metadata is part of its content, so whoever accesses the raw bytes of the file can grab everything in it. Which is not "please don't look" proof. If you
create that on the fly by stripping metadata everytime a download is requested,
or if you do it once to preserve performance and instead occupy space remains your decision.
If there would be something as simple as a "don't show" feature then it would still be in the file and could be extracted easily by software written to ignore that instruction. Seriously, there's no shortcut to that - do it properly and don't spare yourself from getting work done at the wrong end.
I'd like to know if there is a method/application to further compress MP4 files without loss as compressed files (zip-like) for archival purposes, even if I had to make a bigger file before recompressing.
I don't need to play the videos immediately, it's to have a medium to long term backup, so the zipping/unzipping process wouldn't be an issue for me.
Thanks.
No. The last step in video compression is a lossless entropy encoder similar to zip. What you are asking to do has already been done to the file.
I am having trouble doing what the title said. My goal is to be able to add any desired effects to your recording, save the modified audio, then send that to a server.
I have searched the fourms and came across these threads:
viewtopic.php?f=7&t=13029&p=45362&hilit=saving#p45362
viewtopic.php?f=7&t=12660&p=44586&hilit=saving#p44586
viewtopic.php?f=7&t=13178&p=45746&hilit=saving#p45746
After reading those, I see it is possible to save the modified audio, but can it only be saved as a wav? Like I said after it is saved it will be sent to a server, so size is a big deal and wavs are relatively big compared to other formats. Ignoring that fact, I tried to implement FMOD_OUTPUTTYPE_WAVWRITER and I cannot get that to work; are there any good examples of using it? I looked though the examples in the library but I didn't see any..
But the basic structure of the app is to record, turn some switches off and on to see what filters you want, preview it, then press a button "Save" that will save it. What would this save function consist of?
Any help appreciated, thanks.
Using FMOD_OUTPUTTYPE_WAVWRITER is fairly straight forward, you set the type via System::setOutput, specify the output file via System::init extradriverdata. The extradriverdata should be an absolute path to a writable area of the device such as the documents directory. After you have finished playing, call System::release and the file will be complete.
The other option for recording wave data with effects is by creating a custom DSP and connecting it to the channel playing the recorded data. You will then get regular callbacks giving you float data that you must write out to disk yourself. You can find examples of DSPs and writing wav files in the dsp_custom and recordtodisk examples respectively.
Finally note that FMOD doesn't come with the facility to write compressed audio to disk, you will need another API to achieve this goal.
You can save as an AAC file via the ExtAudioFile API.
Alright, what I need is a command-line application that allows you to take a screenshot of a file's audio stream.
For example it should be run like this:
app.exe "C:/artist-title.mp3" "C:/mp3Stream.jpg"
app.exe "C:/artist-title.wav" "C:/wavStream.jpg"
It only has to be able to capture mp3 streams, other streams are a bonus.
Preferably all audio channels are listed in the image, but if all channels are combined into one mono stream it would work just as good for me.
So, is there such a application out there? So that I don't re-invent the wheel.
If not does anyone have tips on how I should go about writing such a application myself? Preferably in Java. I can handle programming pretty well but I'm not exactly an expert on the MP3/WAV formats.
Why do I need it...? Well, it's more fun to link to a file online with some sort of preview image besides the link. It gives you a hint of the audio character before you listen to it (is it loud? does it look like "bit music"? does it have any parts that are more quiet than others? etc).
Never mind, I wrote my own little application in Java.
It was a piece of cake once I found this excellent guide:
http://codeidol.com/java/swing/Audio/Build-an-Audio-Waveform-Display/
Although you can't download the source from that page (as far as I can tell, though he makes it apparent that you should be able to) he does provide some very useful key lines of code that makes it easy to puzzle together the application.
Adding a little bit of help (easy stuff). You can get a graphics object from doing so:
BufferedImage img = new BufferedImage(500, 100, BufferedImage.TYPE_INT_RGB);
Graphics2D gfx = (Graphics2D) img.getGraphics();
And once you have drawn everything you need on the gfx you can save it to disk just by one line:
ImageIO.write(img, "jpg", new File("waveform.png"));
It's hard to get it to look very good though. Doesn't look as nice as for example Audacity. Guess they have spent more time on it than a few hours though.
The biggest pain about this is however that Java don't support MP3 import. They really should get around to that.
So to get the waveform of MP3s I first convert them into WAV using "javazoom.jl.decoder.Decoder.java", it's on their website. Very easy to use, just give the input path and the output path and it's done.
javazoom dot net (couldn't post more than one "hyperlink" on this website)
The big downside of this is of course that a huuge WAV file has to be created, and woe be unto thee if the MP3 happens to be 15 minutes or so... The WAV will be over 100 MiB (maybe even 200 MiB, haven't found out since I got a Java-out-of-memory-error, even though I gave the VM 512mb).
MP3 support in Java today please. Guess the reason they don't have it is because of copyright issues. Copyright really is slowing man down.
Also take a look at http://www.jsresources.org/
It provides a pretty good FAQ section about everything Audio in Java, and some example applications.
I would like to create a quicktime movie from a sequence of still frames via perl. It seems like there should be a relatively simple way to do this, but so far I have not found it. Things I've tried:
Reading the Quicktime file spec and creating the movie file from scratch. This low level approach has worked well for me in the past with TIFF and PDF file formats, but Quicktime seems dauntingly complicated.
Looking at the various quicktime-related perl modules. So far I haven't found one that lets me do what I want (images --> movie) with a minimum of fuss.
Using Applescript and Quicktime Player. This would probably work if I paid for Quicktime Pro, but I'd prefer not to do that.
I'm interested in any suggestions (even non-perl-based ones) for a relatively simple way to assemble a sequence of images into a quicktime movie.
Video encoding isn't really an ideal job for perl -- there are a lot of pieces to put together. I would suggest just using mencoder -- you can use an input of e.g. -mf type=png:fps=30 mf://frame*.png, and an output format of e.g. -of lavf -ovc lavc -lavcopts vcodec=libx264 -o whatever.mov. If you want to dub in audio you can use -audiofile whatever.mp3, and then either -acodec copy if you want it to be MP3 in the movie as well, or perhaps -acodec faac (and -faacopts) if the audio format in the movie needs to be AAC. There are lots of different options to tweak and things to learn but it's pretty much the ideal tool for the job. FFmpeg is nicer to use in a lot of ways, but it doesn't have the mf:// input mode, which makes assembling a video from frames a lot more painful.