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Menus personnalisés
14 novembre 2010, parMediaSPIP utilise le plugin Menus pour gérer plusieurs menus configurables pour la navigation.
Cela permet de laisser aux administrateurs de canaux la possibilité de configurer finement ces menus.
Menus créés à l’initialisation du site
Par défaut trois menus sont créés automatiquement à l’initialisation du site : Le menu principal ; Identifiant : barrenav ; Ce menu s’insère en général en haut de la page après le bloc d’entête, son identifiant le rend compatible avec les squelettes basés sur Zpip ; (...) -
Mise à disposition des fichiers
14 avril 2011, parPar défaut, lors de son initialisation, MediaSPIP ne permet pas aux visiteurs de télécharger les fichiers qu’ils soient originaux ou le résultat de leur transformation ou encodage. Il permet uniquement de les visualiser.
Cependant, il est possible et facile d’autoriser les visiteurs à avoir accès à ces documents et ce sous différentes formes.
Tout cela se passe dans la page de configuration du squelette. Il vous faut aller dans l’espace d’administration du canal, et choisir dans la navigation (...) -
MediaSPIP Player : problèmes potentiels
22 février 2011, parLe lecteur ne fonctionne pas sur Internet Explorer
Sur Internet Explorer (8 et 7 au moins), le plugin utilise le lecteur Flash flowplayer pour lire vidéos et son. Si le lecteur ne semble pas fonctionner, cela peut venir de la configuration du mod_deflate d’Apache.
Si dans la configuration de ce module Apache vous avez une ligne qui ressemble à la suivante, essayez de la supprimer ou de la commenter pour voir si le lecteur fonctionne correctement : /** * GeSHi (C) 2004 - 2007 Nigel McNie, (...)
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-
Encoding images into a movie file
5 avril 2014, par RuAwareI am trying to save jpgs into a movie, I have tried jcodec and alothough my s3 plays it fine other devices do not. including vlc and windows media
I have just spent most of the day playing with MediaCodec, although the SDK is so high, it will help people with jelly bean and above. But I can not work out how to get the Files to the encoder and then write the file.
Ideally I wont to support down to SDK 9/8
Has anyone got any code they can share, either to get MediaCodec to work or another option. If you say ffmpeg, I'd love to but my jin knowledge is non existent and I will need a very good guide.
Code for MediaCodec so far
public class EncodeAndMux extends AsyncTask {
private static int bitRate = 2000000;
private static int MAX_INPUT = 100000;
private static String mimeType = "video/avc";
private int frameRate = 15;
private int colorFormat;
private int stride = 1;
private int sliceHeight = 2;
private MediaCodec encoder = null;
private MediaFormat inputFormat;
private MediaCodecInfo codecInfo = null;
private MediaMuxer muxer;
private boolean mMuxerStarted = false;
private int mTrackIndex = 0;
private long presentationTime = 0;
private Paint bmpPaint;
private static int WAITTIME = 10000;
private static String TAG = "ENCODE";
private ArrayList<string> mFilePaths;
private String mPath;
private EncodeListener mListener;
private int width = 320;
private int height = 240;
private double mSpeed = 1;
public EncodeAndMux(ArrayList<string> filePaths, String savePath) {
mFilePaths = filePaths;
mPath = savePath;
// Create paint to draw BMP
bmpPaint = new Paint();
bmpPaint.setAntiAlias(true);
bmpPaint.setFilterBitmap(true);
bmpPaint.setDither(true);
}
public void setListner(EncodeListener listener) {
mListener = listener;
}
// set the speed, how many frames a second
public void setSpead(int speed) {
mSpeed = speed;
}
public double getSpeed() {
return mSpeed;
}
private long computePresentationTime(int frameIndex) {
final long ONE_SECOND = 1000000;
return (long) (frameIndex * (ONE_SECOND / mSpeed));
}
public interface EncodeListener {
public void finished();
public void errored();
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
@Override
protected Boolean doInBackground(Integer... params) {
try {
muxer = new MediaMuxer(mPath, OutputFormat.MUXER_OUTPUT_MPEG_4);
} catch (Exception e){
e.printStackTrace();
}
// Find a code that supports the mime type
int numCodecs = MediaCodecList.getCodecCount();
for (int i = 0; i < numCodecs && codecInfo == null; i++) {
MediaCodecInfo info = MediaCodecList.getCodecInfoAt(i);
if (!info.isEncoder()) {
continue;
}
String[] types = info.getSupportedTypes();
boolean found = false;
for (int j = 0; j < types.length && !found; j++) {
if (types[j].equals(mimeType))
found = true;
}
if (!found)
continue;
codecInfo = info;
}
for (int i = 0; i < MediaCodecList.getCodecCount(); i++) {
MediaCodecInfo info = MediaCodecList.getCodecInfoAt(i);
if (!info.isEncoder()) {
continue;
}
String[] types = info.getSupportedTypes();
for (int j = 0; j < types.length; ++j) {
if (types[j] != mimeType)
continue;
MediaCodecInfo.CodecCapabilities caps = info.getCapabilitiesForType(types[j]);
for (int k = 0; k < caps.profileLevels.length; k++) {
if (caps.profileLevels[k].profile == MediaCodecInfo.CodecProfileLevel.AVCProfileHigh && caps.profileLevels[k].level == MediaCodecInfo.CodecProfileLevel.AVCLevel4) {
codecInfo = info;
}
}
}
}
Log.d(TAG, "Found " + codecInfo.getName() + " supporting " + mimeType);
MediaCodecInfo.CodecCapabilities capabilities = codecInfo.getCapabilitiesForType(mimeType);
for (int i = 0; i < capabilities.colorFormats.length && colorFormat == 0; i++) {
int format = capabilities.colorFormats[i];
switch (format) {
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Planar:
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedPlanar:
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar:
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedSemiPlanar:
case MediaCodecInfo.CodecCapabilities.COLOR_TI_FormatYUV420PackedSemiPlanar:
colorFormat = format;
break;
}
}
Log.d(TAG, "Using color format " + colorFormat);
// Determine width, height and slice sizes
if (codecInfo.getName().equals("OMX.TI.DUCATI1.VIDEO.H264E")) {
// This codec doesn't support a width not a multiple of 16,
// so round down.
width &= ~15;
}
stride = width;
sliceHeight = height;
if (codecInfo.getName().startsWith("OMX.Nvidia.")) {
stride = (stride + 15) / 16 * 16;
sliceHeight = (sliceHeight + 15) / 16 * 16;
}
inputFormat = MediaFormat.createVideoFormat(mimeType, width, height);
inputFormat.setInteger(MediaFormat.KEY_BIT_RATE, bitRate);
inputFormat.setInteger(MediaFormat.KEY_FRAME_RATE, frameRate);
inputFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT, colorFormat);
inputFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 5);
// inputFormat.setInteger("stride", stride);
// inputFormat.setInteger("slice-height", sliceHeight);
inputFormat.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, MAX_INPUT);
encoder = MediaCodec.createByCodecName(codecInfo.getName());
encoder.configure(inputFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
encoder.start();
ByteBuffer[] inputBuffers = encoder.getInputBuffers();
ByteBuffer[] outputBuffers = encoder.getOutputBuffers();
int inputBufferIndex= -1, outputBufferIndex= -1;
BufferInfo info = new BufferInfo();
for (int i = 0; i < mFilePaths.size(); i++) {
// use decode sample to calculate inSample size and then resize
Bitmap bitmapIn = Images.decodeSampledBitmapFromPath(mFilePaths.get(i), width, height);
// Create blank bitmap
Bitmap bitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
// Center scaled image
Canvas canvas = new Canvas(bitmap);
canvas.drawBitmap(bitmapIn,(bitmap.getWidth()/2)-(bitmapIn.getWidth()/2),(bitmap.getHeight()/2)-(bitmapIn.getHeight()/2), bmpPaint);
Log.d(TAG, "Bitmap width: " + bitmapIn.getWidth() + " height: " + bitmapIn.getHeight() + " WIDTH: " + width + " HEIGHT: " + height);
byte[] dat = getNV12(width, height, bitmap);
bitmap.recycle();
// Exception occurred on this below line in Emulator, LINE No. 182//**
inputBufferIndex = encoder.dequeueInputBuffer(WAITTIME);
Log.i("DAT", "Size= "+dat.length);
if(inputBufferIndex >= 0){
int samplesiz= dat.length;
inputBuffers[inputBufferIndex].put(dat);
presentationTime = computePresentationTime(i);
if (i == mFilePaths.size()) {
encoder.queueInputBuffer(inputBufferIndex, 0, samplesiz, presentationTime, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
Log.i(TAG, "Last Frame");
} else {
encoder.queueInputBuffer(inputBufferIndex, 0, samplesiz, presentationTime, 0);
}
while(true) {
outputBufferIndex = encoder.dequeueOutputBuffer(info, WAITTIME);
Log.i("BATA", "outputBufferIndex="+outputBufferIndex);
if (outputBufferIndex >= 0) {
ByteBuffer encodedData = outputBuffers[outputBufferIndex];
if (encodedData == null) {
throw new RuntimeException("encoderOutputBuffer " + outputBufferIndex +
" was null");
}
if ((info.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.
Log.d(TAG, "ignoring BUFFER_FLAG_CODEC_CONFIG");
info.size = 0;
}
if (info.size != 0) {
if (!mMuxerStarted) {
throw new RuntimeException("muxer hasn't started");
}
// adjust the ByteBuffer values to match BufferInfo (not needed?)
encodedData.position(info.offset);
encodedData.limit(info.offset + info.size);
muxer.writeSampleData(mTrackIndex, encodedData, info);
Log.d(TAG, "sent " + info.size + " bytes to muxer");
}
encoder.releaseOutputBuffer(outputBufferIndex, false);
inputBuffers[inputBufferIndex].clear();
outputBuffers[outputBufferIndex].clear();
if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
break; // out of while
}
} else if (outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
// Subsequent data will conform to new format.
MediaFormat opmediaformat = encoder.getOutputFormat();
if (!mMuxerStarted) {
mTrackIndex = muxer.addTrack(opmediaformat);
muxer.start();
mMuxerStarted = true;
}
Log.i(TAG, "op_buf_format_changed: " + opmediaformat);
} else if(outputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
outputBuffers = encoder.getOutputBuffers();
Log.d(TAG, "Output Buffer changed " + outputBuffers);
} else if(outputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER) {
// No Data, break out
break;
} else {
// Unexpected State, ignore it
Log.d(TAG, "Unexpected State " + outputBufferIndex);
}
}
}
}
if (encoder != null) {
encoder.flush();
encoder.stop();
encoder.release();
encoder = null;
}
if (muxer != null) {
muxer.stop();
muxer.release();
muxer = null;
}
return true;
};
@Override
protected void onPostExecute(Boolean result) {
if (result) {
if (mListener != null)
mListener.finished();
} else {
if (mListener != null)
mListener.errored();
}
super.onPostExecute(result);
}
byte [] getNV12(int inputWidth, int inputHeight, Bitmap scaled) {
int [] argb = new int[inputWidth * inputHeight];
scaled.getPixels(argb, 0, inputWidth, 0, 0, inputWidth, inputHeight);
byte [] yuv = new byte[inputWidth*inputHeight*3/2];
encodeYUV420SP(yuv, argb, inputWidth, inputHeight);
scaled.recycle();
return yuv;
}
void encodeYUV420SP(byte[] yuv420sp, int[] argb, int width, int height) {
final int frameSize = width * height;
int yIndex = 0;
int uvIndex = frameSize;
int a, R, G, B, Y, U, V;
int index = 0;
for (int j = 0; j < height; j++) {
for (int i = 0; i < width; i++) {
a = (argb[index] & 0xff000000) >> 24; // a is not used obviously
R = (argb[index] & 0xff0000) >> 16;
G = (argb[index] & 0xff00) >> 8;
B = (argb[index] & 0xff) >> 0;
// well known RGB to YVU algorithm
Y = ( ( 66 * R + 129 * G + 25 * B + 128) >> 8) + 16;
V = ( ( -38 * R - 74 * G + 112 * B + 128) >> 8) + 128;
U = ( ( 112 * R - 94 * G - 18 * B + 128) >> 8) + 128;
yuv420sp[yIndex++] = (byte) ((Y < 0) ? 0 : ((Y > 255) ? 255 : Y));
if (j % 2 == 0 && index % 2 == 0) {
yuv420sp[uvIndex++] = (byte)((V<0) ? 0 : ((V > 255) ? 255 : V));
yuv420sp[uvIndex++] = (byte)((U<0) ? 0 : ((U > 255) ? 255 : U));
}
index ++;
}
}
}
}
</string></string>This has now been tested on 4 of my devices and works fine, is there are way to
1/ Calculate the MAX_INPUT (to high and on the N7 II it crashes, I Don't want that happening once released)
2/ Offer an api 16 solution ?
3/ Do I need stride and stride height ?Thanks
-
How to extract elementary video from mp4 using ffmpeg programmatically ?
24 octobre 2019, par epipavI have started learning ffmpeg few weaks ago. At the moment I am able to transcode any video to mp4 using h264/AVC codec. The main scheme is something like that :
-open input
-demux
-decode
-encode
-muxThe actual code is below :
#include <iostream>
#include
extern "C" {
#
ifndef __STDC_CONSTANT_MACROS# undef main /* Prevents SDL from overriding main() */ # define __STDC_CONSTANT_MACROS# endif
# pragma comment(lib, "avcodec.lib")# pragma comment(lib, "avformat.lib")# pragma comment(lib, "swscale.lib")# pragma comment(lib, "avutil.lib")
#include
#include
#include
#include
#include <libavutil></libavutil>opt.h>
#include
#include
#include
#include
#include
}
using namespace std;
void open_video(AVFormatContext * oc, AVCodec * codec, AVStream * st) {
int ret;
AVCodecContext * c;
c = st - > codec;
/*open codec */
cout << "probably starts here" << endl;
ret = avcodec_open2(c, codec, NULL);
cout << "and ends here" << endl;
if (ret < 0) {
cout << ("Could not open video codec") << endl;
}
}
/*This function will add a new stream to our file.
@param
oc -> Format context that the new stream will be added.
codec -> codec of the stream, this will be passed.
codec_id ->
chWidth->
chHeight->
*/
AVStream * addStream(AVFormatContext * oc, AVCodec ** codec, enum AVCodecID codec_id, int chWidth, int chHeight, int fps) {
AVCodecContext * c;
AVStream * st;
//find encoder of the stream, it passes this information to @codec, later on
//it will be used in encoding the video @ avcodec_encode_video2 in loop.
* codec = avcodec_find_encoder(AV_CODEC_ID_H264);
if (( * codec) == NULL)
cout << "ERROR CAN NOT FIND ENCODER! ERROR! ERROR! AVCODEC_FIND_ENCODER FAILED !!!1 "
"" << endl;
if (!( * codec))
printf("Could not find encoder for ' %s ' ", avcodec_get_name(codec_id));
//create a new stream with the found codec inside oc(AVFormatContext).
st = avformat_new_stream(oc, * codec);
if (!st)
cout << " Cannot allocate stream " << endl;
//Setting the stream id.
//Since, there can be other streams in this AVFormatContext,
//we should find the first non used index. And this is oc->nb_streams(number of streams) - 1
st - > id = oc - > nb_streams - 1;
c = st - > codec;
//setting the stream's codec's properties.
c - > codec_id = codec_id;
c - > bit_rate = 4000000;
c - > width = chWidth;
c - > height = chHeight;
c - > time_base.den = fps;
//fps;
c - > time_base.num = 1;
c - > gop_size = 12;
c - > pix_fmt = AV_PIX_FMT_YUV420P;
if (c - > codec_id == AV_CODEC_ID_MPEG2VIDEO) {
/* just for testing, we also add B frames */
c - > max_b_frames = 2;
}
if (c - > codec_id == AV_CODEC_ID_MPEG1VIDEO) {
/* Needed to avoid using macroblocks in which some coeffs overflow.
* This does not happen with normal video, it just happens here as
* the motion of the chroma plane does not match the luma plane. */
c - > mb_decision = 2;
}
/* Some formats want stream headers to be separate. */
if (oc - > oformat - > flags & AVFMT_GLOBALHEADER)
c - > flags |= CODEC_FLAG_GLOBAL_HEADER;
//returning our lovely new brand stream.
return st;
}
int changeResolution(string source, int format) {
//Data members
struct SwsContext * sws_ctx = NULL;
AVFrame * pFrame = NULL;
AVFrame * outFrame = NULL;
AVPacket packet;
uint8_t * buffer = NULL;
uint8_t endcode[] = {
0,
0,
1,
0xb7
};
AVDictionary * optionsDict = NULL;
AVFormatContext * pFormatCtx = NULL;
AVFormatContext * outputContext = NULL;
AVCodecContext * pCodecCtx;
AVCodec * pCodec;
AVCodec * codec;
AVCodec * videoCodec;
AVOutputFormat * fmt;
AVStream * video_stream;
int changeWidth;
int changeHeight;
int frameFinished;
int numBytes;
int fps;
int lock = 0;
//Register all codecs & other important stuff. Vital!..
av_register_all();
//Selects the desired resolution.
if (format == 0) {
changeWidth = 320;
changeHeight = 180;
} else if (format == 1) {
changeWidth = 640;
changeHeight = 480;
} else if (format == 2) {
changeWidth = 960;
changeHeight = 540;
} else if (format == 3) {
changeWidth = 1024;
changeHeight = 768;
} else {
changeWidth = 1280;
changeHeight = 720;
}
// Open video file
int aaa;
aaa = avformat_open_input( & pFormatCtx, source.c_str(), NULL, NULL);
if (aaa != 0) {
cout << " cannot open input file \n" << endl;
cout << "aaa = " << aaa << endl;
return -1; // Couldn't open file
}
// Retrieve stream information
if (av_find_stream_info(pFormatCtx) < 0)
return -1; // Couldn't find stream information
//just checking duration casually for no reason
/*int64_t duration = pFormatCtx->duration;
cout << "the duration is " << duration << " " << endl;*/
//this writes the info about the file
av_dump_format(pFormatCtx, 0, 0, 0);
cin >> lock;
// Find the first video stream
int videoStream = -1;
int i;
for (i = 0; i < 3; i++)
if (pFormatCtx - > streams[i] - > codec - > codec_type == AVMEDIA_TYPE_VIDEO) {
videoStream = i;
cout << " lel \n ";
break;
}
if (videoStream == -1)
return -1; // Didn't find a video stream
// Get a pointer to the codec context for the video stream
pCodecCtx = pFormatCtx - > streams[videoStream] - > codec;
fps = pCodecCtx - > time_base.den;
//Find the decoder of the input file, for the video stream
pCodec = avcodec_find_decoder(pCodecCtx - > codec_id);
if (pCodec == NULL) {
fprintf(stderr, "Unsupported codec!\n");
return -1; // Codec not found
}
// Open codec, you must open it first, in order to use it.
if (avcodec_open2(pCodecCtx, pCodec, & optionsDict) < 0)
return -1; // Could not open codec
// Allocate video frame ( pFrame for taking the packets into, outFrame for processed frames to packet.)
pFrame = avcodec_alloc_frame();
outFrame = avcodec_alloc_frame();
i = 0;
int ret;
int video_frame_count = 0;
//Initiate the outFrame set the buffer & fill the properties
numBytes = avpicture_get_size(PIX_FMT_YUV420P, changeWidth, changeHeight);
buffer = (uint8_t * ) av_malloc(numBytes * sizeof(uint8_t));
avpicture_fill((AVPicture * ) outFrame, buffer, PIX_FMT_YUV420P, changeWidth, changeHeight);
int pp;
int frameNo = 0;
//allocate the outputContext, it will be the AVFormatContext of our output file.
//It will try to find the format by giving the file name.
avformat_alloc_output_context2( & outputContext, NULL, NULL, "myoutput.mp4");
//Cant find the file extension, using MPEG as default.
if (!outputContext) {
printf("Could not deduce output format from file extension: using MPEG.\n");
avformat_alloc_output_context2( & outputContext, NULL, "mpeg", "myoutput.mp4");
}
//Still cant set file extension, exit.
if (!outputContext) {
return 1;
}
//set AVOutputFormat fmt to our outputContext's format.
fmt = outputContext - > oformat;
video_stream = NULL;
//If fmt has a valid codec_id, create a new video stream.
//This function will set the streams codec & codecs desired properties.
//Stream's codec will be passed to videoCodec for later usage.
if (fmt - > video_codec != AV_CODEC_ID_NONE)
video_stream = addStream(outputContext, & videoCodec, fmt - > video_codec, changeWidth, changeHeight, fps);
//open the video using videoCodec. by avcodec_open2() i.e open the codec.
if (video_stream)
open_video(outputContext, videoCodec, video_stream);
//Creating our new output file.
if (!(fmt - > flags & AVFMT_NOFILE)) {
ret = avio_open( & outputContext - > pb, "toBeStreamed.264", AVIO_FLAG_WRITE);
if (ret < 0) {
cout << " cant open file " << endl;
return 1;
}
}
//Writing the header of format context.
//ret = avformat_write_header(outputContext, NULL);
if (ret >= 0) {
cout << "writing header success !!!" << endl;
}
//Start reading packages from input file.
while (av_read_frame(pFormatCtx, & packet) >= 0) {
// Is this a packet from the video stream?
if (packet.stream_index == videoStream) {
// Decode video package into frames
ret = avcodec_decode_video2(pCodecCtx, pFrame, & frameFinished, & packet);
if (ret < 0) {
printf(" Error decoding frame !!..");
return ret;
}
if (frameFinished) {
printf("video_frame n:%d coded_n:%d\n", video_frame_count++, pFrame - > coded_picture_number);
}
av_free_packet( & packet);
//do stuff with frame, in this case we are changing the resolution.
static struct SwsContext * img_convert_ctx_in = NULL;
if (img_convert_ctx_in == NULL) {
img_convert_ctx_in = sws_getContext(pCodecCtx - > width,
pCodecCtx - > height,
pCodecCtx - > pix_fmt,
changeWidth,
changeHeight,
PIX_FMT_YUV420P,
SWS_BICUBIC,
NULL,
NULL,
NULL);
}
//scale the frames
sws_scale(img_convert_ctx_in,
pFrame - > data,
pFrame - > linesize,
0,
pCodecCtx - > height,
outFrame - > data,
outFrame - > linesize);
//initiate the pts value
if (frameNo == 0)
outFrame - > pts = 0;
//calculate the pts value & set it.
outFrame - > pts += av_rescale_q(1, video_stream - > codec - > time_base, video_stream - > time_base);
//encode frames into packages. Package passed in @packet.
if (avcodec_encode_video2(outputContext - > streams[0] - > codec, & packet, outFrame, & pp) < 0)
cout << "Encoding frames into packages, failed. " << endl;
frameNo++;
//write the packages into file, resulting in creating a video file.
av_interleaved_write_frame(outputContext, & packet);
}
}
av_free_packet( & packet);
//av_write_trailer(outputContext);
avio_close(outputContext - > pb);
// Free the RGB image
av_free(buffer);
av_free(outFrame);
// Free the YUV frame
av_free(pFrame);
// Close the codec
avcodec_close(video_stream - > codec);
avcodec_close(pCodecCtx);
// Close the video file
avformat_close_input( & pFormatCtx);
return 0;
}
</iostream>at the end of the process I get my desired file with desired codec & container & resolution.
My problem is, in a part of our project I need to get elementary video streams IN file. Such as example.264. However I can not add a stream without creating an AVFormatContext. I can not create an AVFormatContext because 264 files does not have a container,they are just raw video ?, as far as I know.
I have tried the way in decoding_encoding.c which uses fwrite. However that example was for mpeg-2 codec and when I try to adapt that code to H264/AVC codec, I got "floating point division by zero" error from mediainfo and moreover, some of the properties of the video was not showing (such as FPS & playtime & quality factor). I think it has to do with the "endcode" the example adds at the end of the code. It is for mpeg-2. ( uint8_t endcode[] = 0, 0, 1, 0xb7 ; )
Anyway, I would love to get a startpoint for this task. I have managed to come this far by using internet resources ( quite few & outdated for ffmpeg) but now I’m stuck a little.
-
How to extract elementary video from mp4 using ffmpeg programmatically ?
4 juillet 2013, par epipavI have started learning ffmpeg few weaks ago. At the moment I am able to transcode any video to mp4 using h264/AVC codec. The main scheme is something like that :
-open input
demux
decode
encode
muxThe actual code is below :
#include <iostream>
#include
extern "C"
{
#ifndef __STDC_CONSTANT_MACROS
#undef main /* Prevents SDL from overriding main() */
# define __STDC_CONSTANT_MACROS
#endif
#pragma comment (lib,"avcodec.lib")
#pragma comment (lib,"avformat.lib")
#pragma comment (lib,"swscale.lib")
#pragma comment(lib,"avutil.lib")
#include
#include
#include
#include
#include <libavutil></libavutil>opt.h>
#include
#include
#include
#include
#include
}
using namespace std;
void open_video(AVFormatContext*oc , AVCodec *codec, AVStream * st)
{
int ret;
AVCodecContext *c ;
c = st->codec;
/*open codec */
cout << "probably starts here" << endl;
ret = avcodec_open2(c,codec,NULL);
cout << "and ends here" << endl;
if ( ret < 0)
{
cout << ("Could not open video codec") << endl;
}
}
/*This function will add a new stream to our file.
@param
oc -> Format context that the new stream will be added.
codec -> codec of the stream, this will be passed.
codec_id ->
chWidth->
chHeight->
*/
AVStream * addStream(AVFormatContext * oc, AVCodec **codec, enum AVCodecID codec_id, int chWidth, int chHeight, int fps)
{
AVCodecContext *c;
AVStream *st;
//find encoder of the stream, it passes this information to @codec, later on
//it will be used in encoding the video @ avcodec_encode_video2 in loop.
*codec = avcodec_find_encoder(AV_CODEC_ID_H264);
if ( (*codec) == NULL)
cout << "ERROR CAN NOT FIND ENCODER! ERROR! ERROR! AVCODEC_FIND_ENCODER FAILED !!!1 """ << endl;
if(!(*codec))
printf ("Could not find encoder for ' %s ' ", avcodec_get_name(codec_id));
//create a new stream with the found codec inside oc(AVFormatContext).
st = avformat_new_stream ( oc, *codec);
if (!st)
cout << " Cannot allocate stream " << endl;
//Setting the stream id.
//Since, there can be other streams in this AVFormatContext,
//we should find the first non used index. And this is oc->nb_streams(number of streams) - 1
st ->id = oc ->nb_streams - 1;
c = st->codec;
//setting the stream's codec's properties.
c-> codec_id = codec_id;
c->bit_rate = 4000000;
c->width = chWidth;
c->height = chHeight;
c->time_base.den = fps;
//fps;
c->time_base.num = 1;
c->gop_size = 12;
c->pix_fmt = AV_PIX_FMT_YUV420P;
if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
/* just for testing, we also add B frames */
c->max_b_frames = 2;
}
if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
/* Needed to avoid using macroblocks in which some coeffs overflow.
* This does not happen with normal video, it just happens here as
* the motion of the chroma plane does not match the luma plane. */
c->mb_decision = 2;
}
/* Some formats want stream headers to be separate. */
if (oc->oformat->flags & AVFMT_GLOBALHEADER)
c->flags |= CODEC_FLAG_GLOBAL_HEADER;
//returning our lovely new brand stream.
return st;
}
int changeResolution ( string source, int format )
{
//Data members
struct SwsContext *sws_ctx = NULL;
AVFrame *pFrame = NULL;
AVFrame *outFrame = NULL;
AVPacket packet;
uint8_t *buffer = NULL;
uint8_t endcode[] = { 0, 0, 1, 0xb7 };
AVDictionary *optionsDict = NULL;
AVFormatContext *pFormatCtx = NULL;
AVFormatContext *outputContext = NULL;
AVCodecContext *pCodecCtx;
AVCodec *pCodec ;
AVCodec *codec;
AVCodec *videoCodec;
AVOutputFormat *fmt;
AVStream *video_stream;
int changeWidth;
int changeHeight;
int frameFinished;
int numBytes;
int fps;
int lock = 0;
//Register all codecs & other important stuff. Vital!..
av_register_all();
//Selects the desired resolution.
if (format == 0)
{
changeWidth = 320;
changeHeight = 180;
}
else if (format == 1)
{
changeWidth = 640;
changeHeight = 480;
}
else if (format == 2)
{
changeWidth = 960;
changeHeight = 540;
}
else if (format == 3)
{
changeWidth = 1024;
changeHeight = 768;
}
else
{
changeWidth = 1280;
changeHeight = 720;
}
// Open video file
int aaa;
aaa = avformat_open_input(&pFormatCtx, source.c_str(), NULL, NULL) ;
if(aaa !=0)
{
cout << " cannot open input file \n" << endl;
cout << "aaa = " << aaa << endl;
return -1; // Couldn't open file
}
// Retrieve stream information
if(av_find_stream_info(pFormatCtx)<0)
return -1; // Couldn't find stream information
//just checking duration casually for no reason
/*int64_t duration = pFormatCtx->duration;
cout << "the duration is " << duration << " " << endl;*/
//this writes the info about the file
av_dump_format(pFormatCtx, 0, 0, 0);
cin >> lock;
// Find the first video stream
int videoStream=-1;
int i;
for(i=0; i<3; i++)
if(pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
videoStream=i;
cout << " lel \n " ;
break;
}
if(videoStream==-1)
return -1; // Didn't find a video stream
// Get a pointer to the codec context for the video stream
pCodecCtx=pFormatCtx->streams[videoStream]->codec;
fps = pCodecCtx -> time_base.den;
//Find the decoder of the input file, for the video stream
pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
if(pCodec==NULL) {
fprintf(stderr, "Unsupported codec!\n");
return -1; // Codec not found
}
// Open codec, you must open it first, in order to use it.
if(avcodec_open2(pCodecCtx, pCodec, &optionsDict)<0)
return -1; // Could not open codec
// Allocate video frame ( pFrame for taking the packets into, outFrame for processed frames to packet.)
pFrame=avcodec_alloc_frame();
outFrame = avcodec_alloc_frame();
i=0;
int ret;
int video_frame_count = 0;
//Initiate the outFrame set the buffer & fill the properties
numBytes=avpicture_get_size(PIX_FMT_YUV420P, changeWidth, changeHeight);
buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
avpicture_fill((AVPicture *)outFrame, buffer, PIX_FMT_YUV420P, changeWidth, changeHeight );
int pp;
int frameNo = 0;
//allocate the outputContext, it will be the AVFormatContext of our output file.
//It will try to find the format by giving the file name.
avformat_alloc_output_context2(&outputContext,NULL,NULL, "myoutput.mp4");
//Cant find the file extension, using MPEG as default.
if (!outputContext) {
printf("Could not deduce output format from file extension: using MPEG.\n");
avformat_alloc_output_context2(&outputContext, NULL, "mpeg", "myoutput.mp4");
}
//Still cant set file extension, exit.
if (!outputContext) {
return 1;
}
//set AVOutputFormat fmt to our outputContext's format.
fmt = outputContext -> oformat;
video_stream = NULL;
//If fmt has a valid codec_id, create a new video stream.
//This function will set the streams codec & codecs desired properties.
//Stream's codec will be passed to videoCodec for later usage.
if (fmt -> video_codec != AV_CODEC_ID_NONE)
video_stream = addStream(outputContext, &videoCodec, fmt ->video_codec, changeWidth, changeHeight,fps);
//open the video using videoCodec. by avcodec_open2() i.e open the codec.
if (video_stream)
open_video(outputContext, videoCodec, video_stream);
//Creating our new output file.
if (!(fmt->flags & AVFMT_NOFILE)) {
ret = avio_open(&outputContext->pb, "toBeStreamed.264", AVIO_FLAG_WRITE);
if (ret < 0) {
cout << " cant open file " << endl;
return 1;
}
}
//Writing the header of format context.
//ret = avformat_write_header(outputContext, NULL);
if (ret >= 0) {
cout << "writing header success !!!" << endl;
}
//Start reading packages from input file.
while(av_read_frame(pFormatCtx, &packet)>=0 ) {
// Is this a packet from the video stream?
if(packet.stream_index==videoStream) {
// Decode video package into frames
ret = avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
if( ret < 0)
{
printf ( " Error decoding frame !!.." );
return ret;
}
if (frameFinished){
printf("video_frame n:%d coded_n:%d\n" , video_frame_count++, pFrame->coded_picture_number);
}
av_free_packet(&packet);
//do stuff with frame, in this case we are changing the resolution.
static struct SwsContext *img_convert_ctx_in = NULL;
if (img_convert_ctx_in == NULL)
{
img_convert_ctx_in =sws_getContext( pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
changeWidth,
changeHeight,
PIX_FMT_YUV420P,
SWS_BICUBIC,
NULL,
NULL,
NULL );
}
//scale the frames
sws_scale(img_convert_ctx_in,
pFrame->data,
pFrame->linesize,
0,
pCodecCtx->height,
outFrame->data,
outFrame->linesize);
//initiate the pts value
if ( frameNo == 0)
outFrame->pts = 0;
//calculate the pts value & set it.
outFrame->pts += av_rescale_q(1, video_stream->codec->time_base, video_stream->time_base);
//encode frames into packages. Package passed in @packet.
if(avcodec_encode_video2(outputContext->streams[0]->codec, &packet, outFrame, &pp) < 0 )
cout << "Encoding frames into packages, failed. " << endl;
frameNo++;
//write the packages into file, resulting in creating a video file.
av_interleaved_write_frame(outputContext,&packet);
}
}
av_free_packet(&packet);
//av_write_trailer(outputContext);
avio_close(outputContext->pb);
// Free the RGB image
av_free(buffer);
av_free(outFrame);
// Free the YUV frame
av_free(pFrame);
// Close the codec
avcodec_close(video_stream->codec);
avcodec_close(pCodecCtx);
// Close the video file
avformat_close_input(&pFormatCtx);
return 0;
}
</iostream>at the end of the process I get my desired file with desired codec & container & resolution.
My problem is, in a part of our project I need to get elementary video streams IN file. Such as example.264. However I can not add a stream without creating an AVFormatContext. I can not create an AVFormatContext because 264 files does not have a container,they are just raw video ?, as far as I know.
I have tried the way in decoding_encoding.c which uses fwrite. However that example was for mpeg-2 codec and when I try to adapt that code to H264/AVC codec, I got "floating point division by zero" error from mediainfo and moreover, some of the properties of the video was not showing (such as FPS & playtime & quality factor). I think it has to do with the "endcode" the example adds at the end of the code. It is for mpeg-2. ( uint8_t endcode[] = 0, 0, 1, 0xb7 ; )
Anyway, I would love to get a startpoint for this task. I have managed to come this far by using internet resources ( quite few & outdated for ffmpeg) but now I'm stuck a little.
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