l try to read the following video, downloaded from http://www.sample-videos.com/
which is http://www.sample-videos.com/video/mp4/720/big_buck_bunny_720p_5mb.mp4
Here is my code :
import cv2
cap = cv2.VideoCapture('big_buck_bunny_720p_5mb.mp4')
if(cap.isOpened()== False):
print("Error opening video stream or file")
count = 0
while (cap.isOpened()):
# capture frame by frame :
ret, frame = cap.read()
if ret==True:
# Display the resulting frame
cv2.imshow('Frame', frame)
cv2.imwrite("frame%d.jpg" % count, frame)
count +=1
print(count)
However l get Error opening video stream or file at cap = cv2.VideoCapture('big_buck_bunny_720p_5mb.mp4')
and ret equals False always
My OpenCV version is 3.1.0
There may be the following issue with your machine:
configure the video path
check the permission to access the file
install an additional codec
You might have installed opencv but there are some prerequisites needs to be installed while reading a .mp4 video file using open cv.
You can verify that by simply reading an .avi format file and .mp4 file
[it could read .avi file but not .mp4 file]
To read a mp4 .file
Install ffmpeg package compiled with H.264 codec:
H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video.
Ref : https://www.debiantutorials.com/how-to-install-ffmpeg-with-h-264mpeg-4-avc/
Few suggestions to make sure all prerequisites are available
1. check ffmpeg package compiled with H.264 is already installed in the machine using the command below.
ffmpeg -version
2. Installation of open-cv in anaconda will reduce the stress to install ffmpeg package compiled with H.264
3. Make sure that the user created in the machine has got enough privilege to read and write in specific application related directories
a. Check the read and write permission using the command below
ls -ld <folder-path>
or
namei -mo <folder-path>
b. Alter the access writes based on the user privilege required (sudo access needed else we need to engage admin to alter the permission)
eg : sudo chmod -R 740 <folder-path>** [ Recursive rwx for user ,r for group ]
Related
I am trying to transcribe audio from a stream using this tutorial (section, "Performing streaming speech recognition on a local file"): https://cloud.google.com/speech-to-text/docs/streaming-recognize
The file is an M3U file, so I am trying to use the RecognitionConfig.AudioEncoding.MP3 option, but the MP3 attribute is being rejected. When I try to autocomplete the option, MP3 does not appear either.
The documentation show that the MP3 attribute is only available in version v1beta1 (https://cloud.google.com/text-to-speech/docs/reference/rpc/google.cloud.texttospeech.v1beta1#google.cloud.texttospeech.v1beta1.AudioEncoding), and I ran the pip upgrade.
Is there something else I need to do to install v1beta1?
Note that the second link you shared, regarding v1beta1, is for the Text-to-Speech API which is the other way around of the examples you are following (Speech-to-Text API).
In that case, to use RecognitionConfig.AudioEncoding.MP3, you'll need to use the v1p1beta1 version instead. No changes are needed to the pip command (pip install --upgrade google-cloud-speech) but you need to import the right version (speech_v1p1beta1) in your Python code:
# [START speech_transcribe_streaming]
def transcribe_streaming(stream_file):
"""Streams transcription of the given audio file."""
import io
from google.cloud import speech_v1p1beta1
from google.cloud.speech_v1p1beta1 import enums
from google.cloud.speech_v1p1beta1 import types
client = speech_v1p1beta1.SpeechClient()
And now you can use the MP3 encoding:
config = types.RecognitionConfig(
encoding=enums.RecognitionConfig.AudioEncoding.MP3,
sample_rate_hertz=16000,
language_code='en-US')
streaming_config = types.StreamingRecognitionConfig(config=config)
Full code here but it's just the base example with the previous changes.
Tested with an MP3 sample:
$ python mp3.py sample.mp3
Finished: True
Stability: 0.0
Confidence: 0.9875912666320801
Transcript: I'm sorry Dave I'm afraid I can't do that
I just want to get a audio file(opus codec used) only in webm file.
I try to search what is webm format, how to parse, but I cant get info well.
I check that webm format is from mkv, then should I check the mkv first?
there is just one github code, but I cant find way how parse the audio from webm.
https://github.com/webmproject/libwebm/tree/master/webm_parser
You're really going to want the MKVToolNix. These include the tool mkvextract in another answer.
The MKVToolNix is actually a series of tools (mkvmerge, mkvinfo, mkvextract, mkvpropedit). First you asked how to parse the info. You can find the details using:
mkvinfo file.webm
mkvinfo file.webm -a
The first command will parse the overall structure. The second gives the detail of each frame. Use the --help switch if you want all commands.
To extract the audio, do
mkvextract file.webm tracks X:newfile.opus
Where X is the track number that you've identified as wanted from mkvinfo previously. Webm and MKV can have multiple tracks. "newfile.opus" is the new file that you want to create, choose the name you want.
There is also a mkvtoolnix gui, but I've never used that.
mkvextract can extract audio for you, and I recommend having a look at the mkvtoolsnix source code.
For example, you can extract audio from a WebM file into an Ogg Opus file like this:
$ mkvextract ~/audio/bubbles.webm tracks 0:audio.opus
Extracting track 0 with the CodecID 'A_OPUS' to the file 'audio.opus'. Container format: Ogg (Opus in Ogg)
Progress: 100%
I have a file made with a program , an image sticker maker .
I know this program saves it's images(probably an image, a bg and a mask) into single file with extension ".adf" .
I couldn't convert the output file with image magick cause of below error :
convert: no decode delegate for this image format `output.adf' # error/constitute.c/ReadImage/532.
I don't know how this Image converted with Image magick .
it's my -list configure result :
Path: [built-in]
Name Value
-------------------------------------------------------------------------------
NAME ImageMagick
Path: configure.xml
Name Value
-------------------------------------------------------------------------------
CC vs10
COPYRIGHT Copyright (C) 1999-2011 ImageMagick Studio LLC
DELEGATES bzlib freetype jpeg jp2 lcms png tiff x11 xml wmf zlib
FEATURES OpenMP
HOST Windows
LIB_VERSION 0x671
LIB_VERSION_NUMBER 6,7,1,0
NAME ImageMagick
RELEASE_DATE 2011-07-15
VERSION 6.7.1
WEBSITE http:// www.image magick.org
I attached the file :
src.adf
* EDIT *
if I run file command on src.adf it tells :
root#MexHex-PC:# file -vv src.adf
file-5.25
magic file from /etc/magic:/usr/share/misc/magic
What's missed !?
Thanks
This src.adf looks like a very minimal & flat data file. I know nothing about Dalahoo3D and/or ArcGis products, but we can quickly extract the embedded images with python.
import struct
with open('src.adf', 'rb') as f:
# Calculate file size.
f.seek(0, 2)
total_bytes = f.tell()
# Rewind to beging.
f.seek(0)
file_cursor = f.tell()
image_cursor = 0
while file_cursor < total_bytes:
# Can for start of JPEG.
if f.read(1) == b"\xFF":
if f.read(3) == b"\xD8\xFF\xE0":
print("JPEG FOUND!")
# Backup and find the size of the image
f.seek(-8, 1)
payload_size = struct.unpack('<I', f.read(4))[0]
# Write image to disk
d_filename = 'image{0}.jpeg'.format(image_cursor)
with open(d_filename, 'wb') as d:
d.write(f.read(payload_size))
image_cursor += 1
else:
f.seek(-3, 1) # Back cursor up, and try again.
file_cursor = f.tell()
Which dumps the following three images...
I'm sure this file was made with Imagemagick. I had already seen that one would convert the file to tiff image. He told me to do this with Imagemagick but did not explain the method.
I'm guessing this is just a matter of miscommunication. It's true that ImageMagick commonly handles JPEG / TIFF formats, but not geographic information systems and/or 3D modeling. That's usually extended by a vendor -- like ArcGIS. I would bet that ImageMagick is present in the workflow of generating TIFF files, but .ADF wouldn't be supported by ImageMagick until someone writes a delegate coder.
Update
From this question, it looks like you'll need to extend ImageMagick delegates to call GDAL utilities. You'll need to update the delegates.xml file to call the correct utility.
I have added this (https://github.com/kewlbear/FFmpeg-iOS-build-script) version of ffmpeg to my project. I can't see the entry point to the library in the headers included.
How do I get access to the same text command based system that the stand alone application has, or an equivalent?
I would also be happy if someone could point me towards documentation that allows you to use FFmpeg without the command line interface.
This is what I am trying to execute (I have it working on windows and android using the CLI version of ffmpeg)
ffmpeg -framerate 30 -i snap%03d.jpg -itsoffset 00:00:03.23333 -itsoffset 00:00:05 -i soundEffect.WAV -c:v libx264 -vf fps=30 -pix_fmt yuv420p result.mp4
Actually you can build ffmpeg library including the ffmpeg binary's code (ffmpeg.c). Only thing to care about is to rename the function main(int argc, char **argv), for example, to ffmpeg_main(int argc, char **argv) - then you can call it with arguments just like you're executing ffmpeg binary. Note that argv[0] should contain program name, just "ffmpeg" should work.
The same approach was used in the library VideoKit for Android.
To do what you want, you have to use your compiled FFmpeg library in your code.
What you are looking for is exactly the code providing by FFmpeg documentation libavformat/output-example.c (that mean AVFormat and AVCodec FFmpeg's libraries in general).
Stackoverflow is not a "do it for me please" platform. So I prefer explaining here what you have to do, and I will try to be precise and to answer all your questions.
I assume that you already know how to link your compiled (static or shared) library to your Xcode project, this is not the topic here.
So, let's talk about this code. It creates a video (containing video stream and audio stream randomly generated) based on a duration. You want to create a video based on a picture list and sound file. Perfect, there are only three main modifications you have to do:
The end condition is not reaching a duration, but reaching the end of your file list (In code there is already a #define STREAM_NB_FRAMES you can use to iterate over all you frames).
Replace the dummy void fill_yuv_image by your own method that load and decode image buffer from file.
Replace the dummy void write_audio_frame by your own method that load and decode the audio buffer from your file.
(you can find "how to load audio file content" example on documentation starting at line 271, easily adaptable for video content regarding documentation)
In this code, comparing to your CLI, you can figure out that:
const char *filename; in the main should be you output file "result.mp4".
#define STREAM_FRAME_RATE 25 (replace it by 30).
For MP4 generation, video frames will be encoded in H.264 by default (in this code, the GOP is 12). So no need to precise libx264.
#define STREAM_PIX_FMT PIX_FMT_YUV420P represents your desired yuv420p decoding format.
Now, with these official examples and related documentation, you can achieve what you desire. Be careful that there is some differences between FFmpeg's version in these examples and current FFmpeg's version. For example:
st = av_new_stream(oc, 1); // line 60
Could be replaced by:
st = avformat_new_stream(oc, NULL);
st->id = 1;
Or:
if (avcodec_open(c, codec) < 0) { // line 97
Could be replaced by:
if (avcodec_open2(c, codec, NULL) < 0) {
Or again:
dump_format(oc, 0, filename, 1); // line 483
Could be replaced by:
av_dump_format(oc, 0, filename, 1);
Or CODEC_ID_NONE by AV_CODEC_ID_NONE... etc.
Ask your questions, but you got all the keys! :)
MobileFFMpeg is an easy to use pod for the purpose. Instructions on how to use MobileFFMpeg at: https://stackoverflow.com/a/59325680/1466453
MobileFFMpeg gives a very simple method for translating ffmpeg commands to your IOS objective-c program.
Virtually all ffmpeg commands and switches are supported. However you have to get the pod with appropriate license. e.g min-gpl will not give you features of libiconv. libiconv is convered in vidoe, gpl and full-gpl licenses.
Please highlight if you have specific issues regarding use of MobileFFMpeg
Tried a lot of options and am running out of ideas. I was hoping someone here could help. I am trying to write some code in python that will extract frames (say every tenth frame) from a video (.avi or .wmv) and create a picture (.jpg preferably - but other formats will do). I have had no success and was wondering if someone could assist me in solving my problem by providing an alternative to what I have tried and failed.
I have tried PyMedia (the example in their tutorial http://pymedia.org/tut/src/dump_video.py.html does not work - the program bombs out when it looks for the video codecs):
#dm= muxer.Demuxer( inFile.split( '.' )[ -1 ] ) This line does not work
dm= muxer.Demuxer( 'avi' ) #This modified line does seem to work however
i= 1
inFile = "VideoTest.avi"
f= open( inFile, 'rb' )
s= f.read( 400000 )
r= dm.parse( s )
v= filter( lambda x: x[ 'type' ]== muxer.CODEC_TYPE_VIDEO, dm.streams )
v_id= v[ 0 ][ 'index' ]
print 'Assume video stream at %d index: ' % v_id
c= vcodec.Decoder( dm.streams[ v_id ] ) #this is the point where it crashes.
I have tried OpenCV v2.2 for Python but that doesn't work either (I can get most of OpenCV to work - except the one function, CaptureFromFile, that I need does not work). I believe the reason this function doesn't work is because on Windows it requires highGui to operate and for some reason, python and opencv cannot find highgui eventhough it is in the correct directory. I also understand OpenCV has issues with finding and applying correct video codecs so I am not sure which is the cause of my problem.
I have looked at pyFFMPEG but the last build for that was version 2.6 and I am running python 2.7.
I am running this on Windows Vista and Windows 7 machines, have Python 2.7 and OpenCV 2.2 loaded on C:\ and all other python packages (pygames, pymedia, numpy, scipy) installed in C:\python27\Libs\site-packages..." I downloaded and installed from executables, all packages were built for python 2.7. My Path variable includes Python27 and OpenCV and I have a PYTHONPATH variable.
Thanks for any ideas or recommendations.
I tried the following to extract each frames as a separate image:
import cv2
file_path = "some\path\to\the\file.avi"
video_object = cv2.VideoCapture(path)
success = True
while success:
success,frame = video_object.read()
if success:
cv2.imwrite(path[:-4]+"_"+str(i)+".jpg",frame)
print("Done!")
This script saves each frame as an image in the same folder as the source file. It may not be the most efficient way to do this, but it works for me! I know my string parsing is not the most recommended, but it works.
video_object.read() returns two object. The first is a bool indicating whether the reading operation was a success or not, and the second is the image.
There may be limitations with respect to the video codec, of which I am not aware. I'm using Python 2.7 with the most recent version of openCV and Numpy as of 11/7/2013.