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Autres articles (27)
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Publier sur MédiaSpip
13 juin 2013Puis-je poster des contenus à partir d’une tablette Ipad ?
Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir -
ANNEXE : Les plugins utilisés spécifiquement pour la ferme
5 mars 2010, parLe site central/maître de la ferme a besoin d’utiliser plusieurs plugins supplémentaires vis à vis des canaux pour son bon fonctionnement. le plugin Gestion de la mutualisation ; le plugin inscription3 pour gérer les inscriptions et les demandes de création d’instance de mutualisation dès l’inscription des utilisateurs ; le plugin verifier qui fournit une API de vérification des champs (utilisé par inscription3) ; le plugin champs extras v2 nécessité par inscription3 (...)
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Emballe médias : à quoi cela sert ?
4 février 2011, parCe plugin vise à gérer des sites de mise en ligne de documents de tous types.
Il crée des "médias", à savoir : un "média" est un article au sens SPIP créé automatiquement lors du téléversement d’un document qu’il soit audio, vidéo, image ou textuel ; un seul document ne peut être lié à un article dit "média" ;
Sur d’autres sites (7128)
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Audioqueue try to read ADPCM sound
4 septembre 2013, par KamaxI try to read a .asf stream with FFMPEG and the audio part is ADPCM IMA WAV codec.
The sound i hear when i hear something is only noise. I suppose my AudioStreamBasicDescription are wrong. How can i get the correct values ?
From ffprobe i have this :
[STREAM]
index=1
codec_name=adpcm_ima_wav
codec_long_name=ADPCM IMA WAV
codec_type=audio
codec_time_base=1/8000
codec_tag_string=[17][0][0][0]
codec_tag=0x0011
sample_rate=8000.000000
channels=1
bits_per_sample=4
r_frame_rate=0/0
avg_frame_rate=250/41
time_base=1/1000
start_time=0.000000
duration=N/A
[/STREAM]and
Stream #0.1: Audio: adpcm_ima_wav, 8000 Hz, 1 channels, s16, 32 kb/smy code for the moment is :
asbd.mSampleRate = 8000;
asbd.mFormatID = kAudioFormatAppleIMA4;
asbd.mBytesPerPacket = 34;
asbd.mFramesPerPacket = 64;
asdb.mbitsPerChannel = 1;All the rest is to 0 (flags, byte per frame, bits per channel, reserved).
Edit :
I just find that the codec code 17 is maybe for kAudioFormatDVIIntelIMA and not kAudioFormatAppleIMA4. Can someone confirm this ?
This is from ffprobe :
[PACKET]
codec_type=audio
stream_index=1
pts=11200
pts_time=11.200000
dts=11200
dts_time=11.200000
duration=164
duration_time=0.164000
size=656.000000
pos=1171105
flags=K
[/PACKET]Is the size 656 for mBytesperpacket ?
With this value and the half 328 for mFramesPerPacket i can hear something but it's not continuous and has a lot of noise.
Please help !
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Modify H.264 Level in MP4 stream
25 mars 2013, par d33pikaI have 1000+ videos with wrong Level information, and hence do not play on some devices. They are H.264 baseline with aac audio in mp4 container. I want to correct them but avoid re-encoding. Am I right in assuming that this is possible and will be faster ? How do I identify the level_idc bits in the streams ? Will all streams have them in the same location ? I expect this to be in just one place in the stream, is this assumption correct ?
Update : I came across a windows executable link that claims to do this. I want to be able to do this commandline on unix, so I can script it.More Updates : As per Roman's answer below. I dug up MP4 syntax and found that Profile and Level information are part of
avcCatom understsd. I could see that level was set to1E, I corrected it to1F. Before :61 76 63 43 01 42 C0 1E FF E1 00 19 67 42 C0 1E
D9After :
61 76 63 43 01 42 C0 1F FF E1 00 19 67 42 C0 1E
D9with that the MediaInfo changed to :
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L3.0
Format settings, CABAC : No
Format settings, ReFrames : 3 frames
Muxing mode : Container profile=Baseline@3.1
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1mn 4s
Bit rate : 3 000 Kbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 30.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.109
Stream size : 22.7 MiB (92%)
Writing library : x264 core 120 r2151 a3f4407
Encoding settings : cabac=0 / ref=3 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=0 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=abr / mbtree=1 / bitrate=3000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00It introduced a Muxing mode parameter with level
3.1but alas this stream did not play on the device either. How do I correct the level indicated inFormat ProfileIs this possible without re-encoding ? -
Issue in recording video
16 novembre 2015, par human123I am trying to record video in 480*480 resolution like in vine using javacv. As a starting point I used the sample provided in https://github.com/bytedeco/javacv/blob/master/samples/RecordActivity.java Video is getting recorded (but not in the desired resolution) and saved.
But the issue is that 480*480 resolution is not supported natively in android. So some pre processing needs to be done to get the video in desired resolution.
So once I was able to record video using code sample provided by javacv, next challenge was on how to pre process the video. On research it was found that efficient cropping is possible when final image width required is same as recorded image width. Such a solution was provided in the SO question,Recording video on Android using JavaCV (Updated 2014 02 17). I changed onPreviewFrame method as suggested in that answer.
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (audioRecord == null || audioRecord.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING) {
startTime = System.currentTimeMillis();
return;
}
if (RECORD_LENGTH > 0) {
int i = imagesIndex++ % images.length;
yuvImage = images[i];
timestamps[i] = 1000 * (System.currentTimeMillis() - startTime);
}
/* get video data */
imageWidth = 640;
imageHeight = 480
int finalImageHeight = 360;
if (yuvImage != null && recording) {
ByteBuffer bb = (ByteBuffer)yuvImage.image[0].position(0); // resets the buffer
final int startY = imageWidth*(imageHeight-finalImageHeight)/2;
final int lenY = imageWidth*finalImageHeight;
bb.put(data, startY, lenY);
final int startVU = imageWidth*imageHeight + imageWidth*(imageHeight-finalImageHeight)/4;
final int lenVU = imageWidth* finalImageHeight/2;
bb.put(data, startVU, lenVU);
try {
long t = 1000 * (System.currentTimeMillis() - startTime);
if (t > recorder.getTimestamp()) {
recorder.setTimestamp(t);
}
recorder.record(yuvImage);
} catch (FFmpegFrameRecorder.Exception e) {
Log.e(LOG_TAG, "problem with recorder():", e);
}
}
}
}Please also note that this solution was provided for an older version of javacv. The resulting video had a yellowish overlay covering 2/3rd part. Also there was empty section on left side as the video was not cropped correctly.
So my question is what is the most appropriate solution for cropping videos using latest version of javacv ?
Code after making change as suggested by Alex Cohn
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (audioRecord == null || audioRecord.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING) {
startTime = System.currentTimeMillis();
return;
}
if (RECORD_LENGTH > 0) {
int i = imagesIndex++ % images.length;
yuvImage = images[i];
timestamps[i] = 1000 * (System.currentTimeMillis() - startTime);
}
/* get video data */
imageWidth = 640;
imageHeight = 480;
destWidth = 480;
if (yuvImage != null && recording) {
ByteBuffer bb = (ByteBuffer)yuvImage.image[0].position(0); // resets the buffer
int start = 2*((imageWidth-destWidth)/4); // this must be even
for (int row=0; row2; row++) {
bb.put(data, start, destWidth);
start += imageWidth;
}
try {
long t = 1000 * (System.currentTimeMillis() - startTime);
if (t > recorder.getTimestamp()) {
recorder.setTimestamp(t);
}
recorder.record(yuvImage);
} catch (FFmpegFrameRecorder.Exception e) {
Log.e(LOG_TAG, "problem with recorder():", e);
}
}
}Screen shot from video generated with this code (destWidth 480) is
Next I tried capturing a video with destWidth speciified as 639. The result is
When destWidth is 639 video is repeating contents twice. When it is 480, contents are repeated 5 times and the green overlay and distortion is more.
Also When the destWidth = imageWidth, video is captured properly. ie, for 640*480 there is no repetition of video contents and no green overlay.
Converting frame to IplImage
When this question was asked first, I missed to mention that the record method in FFmpegFrameRecorder is now accepting object of type Frame whereas earlier it was IplImage object. So I tried to apply Alex Cohn’s solution by converting Frame to IplImage.
//---------------------------------------
// initialize ffmpeg_recorder
//---------------------------------------
private void initRecorder() {
Log.w(LOG_TAG,"init recorder");
imageWidth = 640;
imageHeight = 480;
if (RECORD_LENGTH > 0) {
imagesIndex = 0;
images = new Frame[RECORD_LENGTH * frameRate];
timestamps = new long[images.length];
for (int i = 0; i < images.length; i++) {
images[i] = new Frame(imageWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
timestamps[i] = -1;
}
} else if (yuvImage == null) {
yuvImage = new Frame(imageWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
Log.i(LOG_TAG, "create yuvImage");
OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();
yuvIplimage = converter.convert(yuvImage);
}
Log.i(LOG_TAG, "ffmpeg_url: " + ffmpeg_link);
recorder = new FFmpegFrameRecorder(ffmpeg_link, imageWidth, imageHeight, 1);
recorder.setFormat("flv");
recorder.setSampleRate(sampleAudioRateInHz);
// Set in the surface changed method
recorder.setFrameRate(frameRate);
Log.i(LOG_TAG, "recorder initialize success");
audioRecordRunnable = new AudioRecordRunnable();
audioThread = new Thread(audioRecordRunnable);
runAudioThread = true;
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (audioRecord == null || audioRecord.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING) {
startTime = System.currentTimeMillis();
return;
}
if (RECORD_LENGTH > 0) {
int i = imagesIndex++ % images.length;
yuvImage = images[i];
timestamps[i] = 1000 * (System.currentTimeMillis() - startTime);
}
/* get video data */
int destWidth = 640;
if (yuvIplimage != null && recording) {
ByteBuffer bb = yuvIplimage.getByteBuffer(); // resets the buffer
int start = 2*((imageWidth-destWidth)/4); // this must be even
for (int row=0; row2; row++) {
bb.put(data, start, destWidth);
start += imageWidth;
}
try {
long t = 1000 * (System.currentTimeMillis() - startTime);
if (t > recorder.getTimestamp()) {
recorder.setTimestamp(t);
}
recorder.record(yuvImage);
} catch (FFmpegFrameRecorder.Exception e) {
Log.e(LOG_TAG, "problem with recorder():", e);
}
}
}But the videos generated with this method contained only green frames.
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