I've always used this command line to create an mp3 with Bit rate: 32kBit / s and Sample rate: 22050 Hz:
"lame -b 32 --resample 22050 input.wav output.mp3"
Now I wanted to use SoxSharp for that, and it has an mp3 option and uses libmp3lame.dll, so I guess it should work.
However, I'm unable to figure the right parameters.
The available parameters for the mp3 output are listed below.
Using nSox As Sox = New Sox("d:\dev\projects\sox-14-4-0\sox.exe")
nSox.Output.Type = FileType.MP3
nSox.Output.SampleRate = I guess that would be 22050 in my case?
nSox.Output.Channels = 1 'yep, I want mono
nSox.Output.Encoding = // not sure what to make of it
nSox.Output.SampleSize = // not sure what to make of it
nSox.Output.ByteOrder = // I guess I shouldn't touch that
nSox.Output.ReverseBits = // I guess I shouldn't touch that
nSox.Output.Compression = // absolutely not sure what I should choose here
nSox.Process("input.wav", "output.mp3")
End Using
Does anybody see where I should insert my "32"? And is .SampleRate = 22050 correct in my case?? The Windows file property dialogue doesn't give me any real hints if I do it correctly, and Audacity converts the audio to the format of my project.
Thank you very much for the help!
Investigating on the source code of SoxSharp, it can't even handle the most basic lame commands out of the box. Basically everything has to be put in the "CustomArguments" property.
Related
I'm trying to use pyav to convert arbitrary audio file to a low quality, mono, wave file.
I almost managed to do it, but it's stereo, and I couldn't find how to make it mono. Furthermore, I think I made some mistake here, as I had to repeat the rate in the output_container.add_stream and in the AudioResampler - it seems redundant, and I can't understand what would happen if those numbers won't match.
My code is:
import av
input_file = 'some.mp3'
output_file = 'new.wav'
rate = 22000
output_container = av.open(output_file, 'w')
# can I tell `output_stream` to just use `resampler`'s info?
# or, if not, how can I tell it to have only 1 channel?
output_stream = output_container.add_stream('pcm_u8', rate)
resampler = av.audio.resampler.AudioResampler('u8p', 'mono', rate)
input_container = av.open(input_file)
for frame in input_container.decode(audio=0):
out_frames = resampler.resample(frame)
for out_frame in out_frames:
for packet in output_stream.encode(out_frame):
output_container.mux(packet)
output_container.close()
And not related to my main question, but any comments regarding my code, or pointing out mistakes, are welcomed. I hardly could find usage examples to use a reference, and PyAV API documentation isn't very detailed...
Searching around in StackOverflow, I found https://stackoverflow.com/a/72386137/1543290 which has:
out_stream = out_container.add_stream(
'pcm_s16le',
rate=sample_rate,
layout='mono'
)
So, the answer is adding layout='mono'.
Sadly, this parameter is not documented.
I am able to use the moviepy library to add a watermark to a section of video. However when I do this it is taking the watermarked segment, and creating a new file with it. I am trying to figure out if it is possible to simply splice in the edited part back into the original video, as moviepy is EXTREMELY slow writing to the disk, so the smaller the segment the better.
I was thinking maybe using shutil?
video = mp.VideoFileClip("C:\\Users\\admin\\Desktop\\Test\\demovideo.mp4").subclip(10,20)
logo = (mp.ImageClip("C:\\Users\\admin\\Desktop\\Watermark\\watermarkpic.png")
.set_duration(20)
.resize(height=20) # if you need to resize...
.margin(right=8, bottom=8, opacity=0) # (optional) logo-border padding
.set_pos(("right","bottom")))
final = mp.CompositeVideoClip([video, logo])
final.write_videofile("C:\\Users\\admin\\Desktop\\output\\demovideo(watermarked).mp4", audio = True, progress_bar = False)
Is there a way to copy the 10 second watermarked snippet back into the original video file? Or is there another library that allows me to do this?
What is slow in your use case is the fact that Moviepy needs to decode and reencode each frame of the movie. If you want speed, I believe there are ways to ask FFMPEG to copy video segments without rencoding.
So you could use ffmpeg to cut the video into 3 subclips (before.mp4/fragment.mp4/after.mp4), only process fragment.mp4, then reconcatenate all clips together with ffmpeg.
The cutting into 3 clips using ffmpeg can be done from moviepy:
https://github.com/Zulko/moviepy/blob/master/moviepy/video/io/ffmpeg_tools.py#L27
However for concatenating everything together you may need to call ffmpeg directly.
I am trying to analyze a wav file in python and get the rms value from the wav. I am using audioop.rms to get the value from the wav. I went to do this and I did not know what fragment and width stood for. I am new to audioop and hope somebody can explain this. I am also wondering if there is any better way to do this in python.
Update: I have done some research and I found out fragment stood for the wav file. I still need to figure out what width means.
A fragment is just a chunk of data. Width is the size in bytes that the data is organized. ex 8bits data has width 1, 16bits has 2 and so on.
```
import alsaaudio, audioop
self.input = alsaaudio.PCM(alsaaudio.PCM_CAPTURE,alsaaudio.PCM_NONBLOCK)
self.input.setchannels(1)
self.input.setrate(8000)
self.input.setformat(alsaaudio.PCM_FORMAT_S16_LE)
self.input.setperiodsize(300)
length, data = self.input.read()
avg_i = audioop.avg(data,2)
```
In the example i am setting alsa capture card to use a S16_LE signed 16bits Little Endian, so I have to set width to be 2. For the fragment is just the data captured by alsa. In your case the wav file is your data.
I'm trying to convert DVD iso files to mp4 using HandbrakeCLI. I use the following line in a batch file:
D:\HandBrakeCLI.exe -i "D:\input.iso" -o "D:\output.mp4" --no-markers --width "720" --height "480" --preset "HQ 480p30 Surround" --encoder "mpeg2" --audio-lang-list "eng"
When I do this, I must then extract the audio from the file, using the following line:
D:\eac3to\eac3to.exe "D:\output.mp4" "D:\output.wavs" -down16
However, when I attempt to extract the audio, I get the error message
The format of the source file could not be detected.
Is there anything wrong with my former line of code that's causing the mp4 to get screwed up?
Minor side question: I'm also trying to get handbrake to remove subtitles and also only keep English audio, do you know what code could be used for that? I started a bit there with the --audio-lang-list "eng" but I'm now sure what to do from there.
Thanks a lot in advance!
You need to use a valid audio format. .wavs is not valid. You have to use an available audio codec to output to the below for --aencoder. The default output audio for MP4 is .aac
av_aac
copy:aac
ac3
copy:ac3
eac3
copy:eac3
copy:truehd
copy:dts
copy:dtshd
mp3
copy:mp3
vorbis
flac16
flac24
copy:flac
opus
copy
Defaults for audio
av_mp4 = av_aac
av_mkv = mp3
You need to pass none for no subtitles
-s none
And define only eng track like you were doing
--audio-lang-list eng
Check out the Handbrake CLI Documentation for the command line code:
https://handbrake.fr/docs/en/latest/cli/cli-guide.html
You can also try using a different program once you extract the audio. A program like XMediaRecode. It can also remux audio and video and convert other audio formats to wav
https://www.videohelp.com/software/XMedia-Recode
I am trying to write a C++/Qt program for linux, where I take a still image photo from a webcam, make some transformations to a photo (cropping, resizing, etc.), and save it to a jpeg file.
But I have encountered some problems. The main problem is that standart UVC (usb video device class) linux driver currently does not support direct still image capture: http://www.ideasonboard.org/uvc/ .
So, there are two possible ways to capture still image. You can take one frame from the video stream from the camera, or you can take a separate photo, like a digital portable camera. The second way is not supported in linux uvc driver, so the first method is the only way. But the problem is, that if you want to take a frame from the video stream, the size of the photo can't be bigger than the size of video in the video preview window. So, if I want to take 2 megapixel photo, I must start videostream with the size 1600x1200, which is not so comfortable (At least, in Qt the size of the videostream depends on the videopreview window size).
I know that there is video for linux 2 API, which may be helpful in this task, but I don't know how to use it. I am currently learning gstreamer, but I can't now figure out how to do what I need using these tools.
So, I will appreciate any help. I think it is not a hard problem for people who know Linux, GStreamer, v4l2 API, and other linux-specific things.
By the way, the program will be used only with web-camera Logitech C270 HD.
Please, help me. I don't know what API or framework can help me do this. May be you know.
Unfortunately the C4V2 calls in opencv did not work for still image capture with any camera I have tried out of the box using the UVC driver.
To debug the issue I have been playing with trying to accomplish this with c code calling c4v2 directly.
I have been playing with the example code found here. It uses the method of pulling frames from the video stream.
You can compile it with:
gcc -O2 -Wall `pkg-config --cflags --libs libv4l2` filename.c -o filename
I have experimented with 3 logitech cameras. The best of the lot seems to be the Logitech C910. But even it has significant issues.
Here are the problems I have encountered trying to accomplish your same task with this code.
It works pretty much every time with width and height set to 1920x1080.
When I query other possibilities directly from the command line using for example:
v4l2-ctl --list-formats-ext
and I try some of the other "available" smaller sizes it hangs in the select waiting for the camera to release the buffer.
Also when I try to set other sizes directly from the command line using for example:
v4l2-ctl -v height=320 -v width=240 -v pixelformat=YUYV
Then check with
v4l2-ctl -V
I find that it returns the correct pixel format but quite often not the correct size.
Apparently this camera which is listed on the UVC site as being UVC and therefore v4l2 compatible is not up to snuff. I suspect it is just as bad for other cameras. The other two I tried were also listed as compatible on the site but had worse problems.
I did some more testing on the LogitechC910 after I posted this. I thought I would post the results in case it helps someone else out.
I wrote a script to test v4l2 grabber code mentioned above on all the formats the camera claims it supports when it is queried with v4l2 here are the results:
640x480 => Hangs on clearing buffer
160x120 => Works
176x144 => Works
320x176 => Works
320x240 => Works
432x240 => Works
352x288 => Works
544x288 => Works
640x360 => Works
752x416 => Hangs on clearing buffer
800x448 => Hangs on clearing buffer
864x480 => Works
960x544 => Works
1024x576 => Works
800x600 => Works
1184x656 => Works
960x720 => Works
1280x720 => Works
1392x768 => Works
1504x832 => Works
1600x896 => Works
1280x960 => Works
1712x960 => Works
1792x1008 => Works
1920x1080 => Works
1600x1200 => Works
2048x1536 => Works
2592x1944 => Hangs on clearing buffer.
It turns out that the default setting of 640x480 doesnt work and that is what trapped me and most others who have posted on message boards.
Since it is grabbing a video frame the first frame it grabs when starting up may have incorrect exposure (often black or close to it). I believe this is because since it is being used as a video camera it adjusts exposure as it goes and doesnt care about the first frames. I believe this also trapped me and other who saw the first frame as black or nearly black and thought it was some kind of error. Later frames have the correct exposure
It turns out that opencv with python wrappers works fine with this camera if you avoid the land mines listed above and ignore all the error messages. The error messages are due to the fact while the camera accepts v4l2 commands it doesnt respond correctly. So if you set the width it actually gets set correctly but it responds with an incorrect width.
To run under opencv with python wrappers you can do the following:
import cv2
import numpy
cap = cv2.VideoCapture(0) #ignore the errors
cap.set(3, 960) #Set the width important because the default will timeout
#ignore the error or false response
cap.set(4, 544) #Set the height ignore the errors
r, frame = cap.read()
cv2.imwrite("test.jpg", frame)
**Download And Install 'mplayer'**
mplayer -vo png -frames 1 tv://
mplayer -vo png -frames 1 tv://
might give a green screen output as the camera is not yet ready.
mplayer -vo png -frames 2 tv://
You can try increasing the number of frames and choose a number from which the camera gives correct images.
What about this program?
#include<opencv2/opencv.hpp>
using namespace cv;
int main()
{
VideoCapture webcam;
webcam.open(0);
Mat frame;
char key;
while(true)
{
webcam >> frame;
imshow("My Webcam",frame);
key = waitKey(10);
if(key=='s')
break;
}
imwrite("webcam_capture.jpg", frame);
webcam.release();
return 0;
}
This will capture a picture of maximum size allowed by your webcam. Now you can add effects or resize the captured image with Qt. And OpenCV is very very easy to integrate with Qt, :)