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Autres articles (98)
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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 -
Supporting all media types
13 avril 2011, parUnlike most software and media-sharing platforms, MediaSPIP aims to manage as many different media types as possible. The following are just a few examples from an ever-expanding list of supported formats : images : png, gif, jpg, bmp and more audio : MP3, Ogg, Wav and more video : AVI, MP4, OGV, mpg, mov, wmv and more text, code and other data : OpenOffice, Microsoft Office (Word, PowerPoint, Excel), web (html, CSS), LaTeX, Google Earth and (...)
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Support de tous types de médias
10 avril 2011Contrairement à beaucoup de logiciels et autres plate-formes modernes de partage de documents, MediaSPIP a l’ambition de gérer un maximum de formats de documents différents qu’ils soient de type : images (png, gif, jpg, bmp et autres...) ; audio (MP3, Ogg, Wav et autres...) ; vidéo (Avi, MP4, Ogv, mpg, mov, wmv et autres...) ; contenu textuel, code ou autres (open office, microsoft office (tableur, présentation), web (html, css), LaTeX, Google Earth) (...)
Sur d’autres sites (6192)
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Anomalie #2915 : dans privé en colonne gauche dans h3, chevauchement texte sur lien "plus d’info"
3 mai 2015, par chan kalanavec Firefox 37.0.1 et SPIP 3.1.0 Alpha r"je sais pas combien", ça n’a pas vraiment changé depuis SPIP 2...
je reproduis dans tous les navigateurs sur Linux : Chrome, Opéra etc... -
MediaCodec - save timing info for ffmpeg ?
18 novembre 2014, par MarkI have a requirement to encrypt video before it hits the disk. It seems on Android the only way to do this is to use MediaCodec, and encrypt and save the raw h264 elementary streams. (The MediaRecorder and Muxer classes operate on FileDescriptors, not an OutputStream, so I can’t wrap it with a CipherOutputStream).
Using the grafika code as a base, I’m able to save a raw h264 elementary stream by replacing the Muxer in the VideoEncoderCore class with a WriteableByteChannel, backed by a CipherOutputStream (code below, minus the CipherOutputStream).
If I take the resulting output file over to the desktop I’m able to use ffmpeg to mux the h264 stream to a playable mp4 file. What’s missing however is timing information. ffmpeg always assumes 25fps. What I’m looking for is a way to save the timing info, perhaps to a separate file, that I can use to give ffmpeg the right information on the desktop.
I’m not doing audio yet, but I can imagine I’ll need to do the same thing there, if I’m to have any hope of remotely accurate syncing.
FWIW, I’m a total newbie here, and I really don’t know much of anything about SPS, NAL, Atoms, etc.
/*
* Copyright 2014 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.util.Log;
import android.view.Surface;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.WritableByteChannel;
/**
* This class wraps up the core components used for surface-input video encoding.
* <p>
* Once created, frames are fed to the input surface. Remember to provide the presentation
* time stamp, and always call drainEncoder() before swapBuffers() to ensure that the
* producer side doesn't get backed up.
* </p><p>
* This class is not thread-safe, with one exception: it is valid to use the input surface
* on one thread, and drain the output on a different thread.
*/
public class VideoEncoderCore {
private static final String TAG = MainActivity.TAG;
private static final boolean VERBOSE = false;
// TODO: these ought to be configurable as well
private static final String MIME_TYPE = "video/avc"; // H.264 Advanced Video Coding
private static final int FRAME_RATE = 30; // 30fps
private static final int IFRAME_INTERVAL = 5; // 5 seconds between I-frames
private Surface mInputSurface;
private MediaCodec mEncoder;
private MediaCodec.BufferInfo mBufferInfo;
private int mTrackIndex;
//private MediaMuxer mMuxer;
//private boolean mMuxerStarted;
private WritableByteChannel outChannel;
/**
* Configures encoder and muxer state, and prepares the input Surface.
*/
public VideoEncoderCore(int width, int height, int bitRate, File outputFile)
throws IOException {
mBufferInfo = new MediaCodec.BufferInfo();
MediaFormat format = MediaFormat.createVideoFormat(MIME_TYPE, width, height);
// Set some properties. Failing to specify some of these can cause the MediaCodec
// configure() call to throw an unhelpful exception.
format.setInteger(MediaFormat.KEY_COLOR_FORMAT,
MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
format.setInteger(MediaFormat.KEY_BIT_RATE, bitRate);
format.setInteger(MediaFormat.KEY_FRAME_RATE, FRAME_RATE);
format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, IFRAME_INTERVAL);
if (VERBOSE) Log.d(TAG, "format: " + format);
// Create a MediaCodec encoder, and configure it with our format. Get a Surface
// we can use for input and wrap it with a class that handles the EGL work.
mEncoder = MediaCodec.createEncoderByType(MIME_TYPE);
mEncoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mInputSurface = mEncoder.createInputSurface();
mEncoder.start();
// Create a MediaMuxer. We can't add the video track and start() the muxer here,
// because our MediaFormat doesn't have the Magic Goodies. These can only be
// obtained from the encoder after it has started processing data.
//
// We're not actually interested in multiplexing audio. We just want to convert
// the raw H.264 elementary stream we get from MediaCodec into a .mp4 file.
//mMuxer = new MediaMuxer(outputFile.toString(),
// MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
mTrackIndex = -1;
//mMuxerStarted = false;
outChannel = Channels.newChannel(new BufferedOutputStream(new FileOutputStream(outputFile)));
}
/**
* Returns the encoder's input surface.
*/
public Surface getInputSurface() {
return mInputSurface;
}
/**
* Releases encoder resources.
*/
public void release() {
if (VERBOSE) Log.d(TAG, "releasing encoder objects");
if (mEncoder != null) {
mEncoder.stop();
mEncoder.release();
mEncoder = null;
}
try {
outChannel.close();
}
catch (Exception e) {
Log.e(TAG,"Couldn't close output stream.");
}
}
/**
* Extracts all pending data from the encoder and forwards it to the muxer.
* </p><p>
* If endOfStream is not set, this returns when there is no more data to drain. If it
* is set, we send EOS to the encoder, and then iterate until we see EOS on the output.
* Calling this with endOfStream set should be done once, right before stopping the muxer.
* </p><p>
* We're just using the muxer to get a .mp4 file (instead of a raw H.264 stream). We're
* not recording audio.
*/
public void drainEncoder(boolean endOfStream) {
final int TIMEOUT_USEC = 10000;
if (VERBOSE) Log.d(TAG, "drainEncoder(" + endOfStream + ")");
if (endOfStream) {
if (VERBOSE) Log.d(TAG, "sending EOS to encoder");
mEncoder.signalEndOfInputStream();
}
ByteBuffer[] encoderOutputBuffers = mEncoder.getOutputBuffers();
while (true) {
int encoderStatus = mEncoder.dequeueOutputBuffer(mBufferInfo, TIMEOUT_USEC);
if (encoderStatus == MediaCodec.INFO_TRY_AGAIN_LATER) {
// no output available yet
if (!endOfStream) {
break; // out of while
} else {
if (VERBOSE) Log.d(TAG, "no output available, spinning to await EOS");
}
} else if (encoderStatus == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
// not expected for an encoder
encoderOutputBuffers = mEncoder.getOutputBuffers();
} else if (encoderStatus == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
// should happen before receiving buffers, and should only happen once
//if (mMuxerStarted) {
// throw new RuntimeException("format changed twice");
//}
MediaFormat newFormat = mEncoder.getOutputFormat();
Log.d(TAG, "encoder output format changed: " + newFormat);
// now that we have the Magic Goodies, start the muxer
//mTrackIndex = mMuxer.addTrack(newFormat);
//mMuxer.start();
//mMuxerStarted = true;
} else if (encoderStatus < 0) {
Log.w(TAG, "unexpected result from encoder.dequeueOutputBuffer: " +
encoderStatus);
// let's ignore it
} else {
ByteBuffer encodedData = encoderOutputBuffers[encoderStatus];
if (encodedData == null) {
throw new RuntimeException("encoderOutputBuffer " + encoderStatus +
" was null");
}
/*
FFMPEG needs this info.
if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
// The codec config data was pulled out and fed to the muxer when we got
// the INFO_OUTPUT_FORMAT_CHANGED status. Ignore it.
if (VERBOSE) Log.d(TAG, "ignoring BUFFER_FLAG_CODEC_CONFIG");
mBufferInfo.size = 0;
}
*/
if (mBufferInfo.size != 0) {
/*
if (!mMuxerStarted) {
throw new RuntimeException("muxer hasn't started");
}
*/
// adjust the ByteBuffer values to match BufferInfo (not needed?)
encodedData.position(mBufferInfo.offset);
encodedData.limit(mBufferInfo.offset + mBufferInfo.size);
try {
outChannel.write(encodedData);
}
catch (Exception e) {
Log.e(TAG,"Error writing output.",e);
}
if (VERBOSE) {
Log.d(TAG, "sent " + mBufferInfo.size + " bytes to muxer, ts=" +
mBufferInfo.presentationTimeUs);
}
}
mEncoder.releaseOutputBuffer(encoderStatus, false);
if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
if (!endOfStream) {
Log.w(TAG, "reached end of stream unexpectedly");
} else {
if (VERBOSE) Log.d(TAG, "end of stream reached");
}
break; // out of while
}
}
}
}
}
</p> -
FPS from RTSP stream info does not match actual framerate
17 mai 2021, par KrapowI have a 25FPS RTSP stream coming from an IP-camera. I can successfully display the video stream. But when analyzing the stream with ffmpeg (ffprobe actually), I observe fewer frames per second rate :


$ ffprobe -rtsp_transport tcp -i rtsp://camera_ip:554/stream -select_streams v:0 -show_frames -show_entries frame=coded_picture_number,pkt_pts_time -of csv=p=0
Stream #0:0: Video: h264 (Main), yuvj420p(pc, bt709, progressive), 640x480, 25 fps, 25 tbr, 90k tbn, 50 tbc
0.400000,0
0.080000,1
0.120000,2
0.200000,3
0.240000,4
0.320000,5
0.360000,6
0.440000,7
0.480000,8
0.560000,9
0.600000,10
0.680000,11
0.720000,12
0.800000,13
0.840000,14
0.920000,15
0.960000,16
1.040000,17
1.080000,18
1.160000,19
1.200000,20
1.280000,21
1.320000,22
1.400000,23
1.440000,24
1.520000,25
1.560000,26
1.640000,27
1.680000,28
1.760000,29
1.800000,30
1.880000,31
1.920000,32
2.000000,33


We can clearly see the 80ms gap between some of the frames, resulting in a 16fps stream.


I have observed the same framerate issue with GStreamer (printing information in the rtpjitterbuffer indicates the frame gap is sometimes 80ms and sometimes 40ms). But the weird thing is, I encountered the same issue with an HDMI-RJ45 decoder, and I doubt the same issue comes from 2 different devices.
I didn't get much more informations using -loglevel debug or trace.
Does anybody have an idea about what is going wrong in the stream ?


(I used ffprobe 4.2.3 and the last "2021-05-09-git-8649f5dca6-full_build-www.gyan.dev" with the same results, and GStreamer 1.16.2 with a pipeline like "urisourcebin ! h264depay ! h264parse ! fakesink")


EDIT : The camera skipping of frames was caused by the activation of a third stream in the options. I find it really weird that it skips exactly the same frames every seconds. However, I still haven't found the cause of the downrate on my RTSP encoder.
Anyway, this was actually hardware related and not software related.


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