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Médias (1)
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Somos millones 1
21 juillet 2014, par
Mis à jour : Juin 2015
Langue : français
Type : Video
Autres articles (22)
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Qualité du média après traitement
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Plus la qualité du média est importante, plus la bande passante sera utilisée. Le visiteur avec une connexion internet à petit débit devra attendre plus longtemps. Inversement plus, la qualité du média est pauvre et donc le média devient dégradé voire (...) -
Ecrire une actualité
21 juin 2013, parPrésentez les changements dans votre MédiaSPIP ou les actualités de vos projets sur votre MédiaSPIP grâce à la rubrique actualités.
Dans le thème par défaut spipeo de MédiaSPIP, les actualités sont affichées en bas de la page principale sous les éditoriaux.
Vous pouvez personnaliser le formulaire de création d’une actualité.
Formulaire de création d’une actualité Dans le cas d’un document de type actualité, les champs proposés par défaut sont : Date de publication ( personnaliser la date de publication ) (...) -
XMP PHP
13 mai 2011, parDixit Wikipedia, XMP signifie :
Extensible Metadata Platform ou XMP est un format de métadonnées basé sur XML utilisé dans les applications PDF, de photographie et de graphisme. Il a été lancé par Adobe Systems en avril 2001 en étant intégré à la version 5.0 d’Adobe Acrobat.
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Anomalie #3708 (Fermé) : .select dans menu lateral
17 mars 2016, par b bLes specs pour la structure html des formulaires indiquent bien que :
Chaque champ de saisie est encapsulé dans un élément de classe .editer, qui doivent être regroupés dans un élement de classe .editer-groupe.
http://www.spip.net/fr_article3791.html
Du coup, en suivant les specs ton plugin n’aurait pas ce bug, donc il faut bien ajouter une classe editer dans ton plugin.
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Encoding Exception during Transcode with audio files
6 mai 2016, par Hakop ZakaryanI am attempting to transcode using an FFMPEG Wrapper Library called JAVE on Mac OSX 10.11.3 using Eclipse 4.50
My Converter.java class looks something like this :
package matador;
import it.sauronsoftware.jave.AudioAttributes;
import it.sauronsoftware.jave.EncodingAttributes;
import it.sauronsoftware.jave.EncoderException;
import it.sauronsoftware.jave.InputFormatException;
import it.sauronsoftware.jave.Encoder;
import java.io.*;
public class Converter {
public static void main(String[] args) throws InputFormatException, EncoderException {
File source = new File("Classic.m4a");
File target = new File("target.mp3");
AudioAttributes audio = new AudioAttributes();
audio.setCodec("libmp3lame");
audio.setBitRate(new Integer(128000));
audio.setChannels(new Integer(2));
audio.setSamplingRate(new Integer(44100));
EncodingAttributes attrs = new EncodingAttributes();
attrs.setFormat("mp3");
attrs.setAudioAttributes(audio);
Encoder encoder = new Encoder(new MyFFMPEGExecutableLocator());
try {
encoder.encode(source, target, attrs, null);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (InputFormatException e) {
e.printStackTrace();
} catch (EncoderException e) {
e.printStackTrace();
}
}
}The problem I am running into is that with specific audio files (regardless of format) give me this EncoderException :
it.sauronsoftware.jave.EncoderException: Metadata:
at it.sauronsoftware.jave.Encoder.encode(Encoder.java:863)
at matador.Converter.main(Converter.java:32)I have looked through Encoder.java and the EncoderException on line 863 is this specific code :
} else if (!line.startsWith("Output #0")) {
throw new EncoderException(line);I have been unable to figure out why this may be occurring but specific audio files (WAV/AAC/etc) do encode yet a majority just give this exception.
Thank you for the help !
Edit : As per request for possibly being able to help me further, here is the entirety of the Encoder.java code :
package it.sauronsoftware.jave;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Encoder {
private static final Pattern FORMAT_PATTERN = Pattern
.compile("^\\s*([D ])([E ])\\s+([\\w,]+)\\s+.+$");
private static final Pattern ENCODER_DECODER_PATTERN = Pattern.compile(
"^\\s*([D ])([E ])([AVS]).{3}\\s+(.+)$", Pattern.CASE_INSENSITIVE);
private static final Pattern PROGRESS_INFO_PATTERN = Pattern.compile(
"\\s*(\\w+)\\s*=\\s*(\\S+)\\s*", Pattern.CASE_INSENSITIVE);
private static final Pattern SIZE_PATTERN = Pattern.compile(
"(\\d+)x(\\d+)", Pattern.CASE_INSENSITIVE);
private static final Pattern FRAME_RATE_PATTERN = Pattern.compile(
"([\\d.]+)\\s+(?:fps|tb\\(r\\))", Pattern.CASE_INSENSITIVE);
private static final Pattern BIT_RATE_PATTERN = Pattern.compile(
"(\\d+)\\s+kb/s", Pattern.CASE_INSENSITIVE);
private static final Pattern SAMPLING_RATE_PATTERN = Pattern.compile(
"(\\d+)\\s+Hz", Pattern.CASE_INSENSITIVE);
private static final Pattern CHANNELS_PATTERN = Pattern.compile(
"(mono|stereo)", Pattern.CASE_INSENSITIVE);
private static final Pattern SUCCESS_PATTERN = Pattern.compile(
"^\\s*video\\:\\S+\\s+audio\\:\\S+\\s+global headers\\:\\S+.*$",
Pattern.CASE_INSENSITIVE);
private FFMPEGLocator locator;
public Encoder() {
this.locator = new DefaultFFMPEGLocator();
}
public Encoder(FFMPEGLocator locator) {
this.locator = locator;
}
public String[] getAudioDecoders() throws EncoderException {
ArrayList res = new ArrayList();
FFMPEGExecutor ffmpeg = locator.createExecutor();
ffmpeg.addArgument("-formats");
try {
ffmpeg.execute();
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getInputStream()));
String line;
boolean evaluate = false;
while ((line = reader.readLine()) != null) {
if (line.trim().length() == 0) {
continue;
}
if (evaluate) {
Matcher matcher = ENCODER_DECODER_PATTERN.matcher(line);
if (matcher.matches()) {
String decoderFlag = matcher.group(1);
String audioVideoFlag = matcher.group(3);
if ("D".equals(decoderFlag)
&& "A".equals(audioVideoFlag)) {
String name = matcher.group(4);
res.add(name);
}
} else {
break;
}
} else if (line.trim().equals("Codecs:")) {
evaluate = true;
}
}
} catch (IOException e) {
throw new EncoderException(e);
} finally {
ffmpeg.destroy();
}
int size = res.size();
String[] ret = new String[size];
for (int i = 0; i < size; i++) {
ret[i] = (String) res.get(i);
}
return ret;
}
public String[] getAudioEncoders() throws EncoderException {
ArrayList res = new ArrayList();
FFMPEGExecutor ffmpeg = locator.createExecutor();
ffmpeg.addArgument("-formats");
try {
ffmpeg.execute();
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getInputStream()));
String line;
boolean evaluate = false;
while ((line = reader.readLine()) != null) {
if (line.trim().length() == 0) {
continue;
}
if (evaluate) {
Matcher matcher = ENCODER_DECODER_PATTERN.matcher(line);
if (matcher.matches()) {
String encoderFlag = matcher.group(2);
String audioVideoFlag = matcher.group(3);
if ("E".equals(encoderFlag)
&& "A".equals(audioVideoFlag)) {
String name = matcher.group(4);
res.add(name);
}
} else {
break;
}
} else if (line.trim().equals("Codecs:")) {
evaluate = true;
}
}
} catch (IOException e) {
throw new EncoderException(e);
} finally {
ffmpeg.destroy();
}
int size = res.size();
String[] ret = new String[size];
for (int i = 0; i < size; i++) {
ret[i] = (String) res.get(i);
}
return ret;
}
public String[] getVideoDecoders() throws EncoderException {
ArrayList res = new ArrayList();
FFMPEGExecutor ffmpeg = locator.createExecutor();
ffmpeg.addArgument("-formats");
try {
ffmpeg.execute();
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getInputStream()));
String line;
boolean evaluate = false;
while ((line = reader.readLine()) != null) {
if (line.trim().length() == 0) {
continue;
}
if (evaluate) {
Matcher matcher = ENCODER_DECODER_PATTERN.matcher(line);
if (matcher.matches()) {
String decoderFlag = matcher.group(1);
String audioVideoFlag = matcher.group(3);
if ("D".equals(decoderFlag)
&& "V".equals(audioVideoFlag)) {
String name = matcher.group(4);
res.add(name);
}
} else {
break;
}
} else if (line.trim().equals("Codecs:")) {
evaluate = true;
}
}
} catch (IOException e) {
throw new EncoderException(e);
} finally {
ffmpeg.destroy();
}
int size = res.size();
String[] ret = new String[size];
for (int i = 0; i < size; i++) {
ret[i] = (String) res.get(i);
}
return ret;
}
public String[] getVideoEncoders() throws EncoderException {
ArrayList res = new ArrayList();
FFMPEGExecutor ffmpeg = locator.createExecutor();
ffmpeg.addArgument("-formats");
try {
ffmpeg.execute();
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getInputStream()));
String line;
boolean evaluate = false;
while ((line = reader.readLine()) != null) {
if (line.trim().length() == 0) {
continue;
}
if (evaluate) {
Matcher matcher = ENCODER_DECODER_PATTERN.matcher(line);
if (matcher.matches()) {
String encoderFlag = matcher.group(2);
String audioVideoFlag = matcher.group(3);
if ("E".equals(encoderFlag)
&& "V".equals(audioVideoFlag)) {
String name = matcher.group(4);
res.add(name);
}
} else {
break;
}
} else if (line.trim().equals("Codecs:")) {
evaluate = true;
}
}
} catch (IOException e) {
throw new EncoderException(e);
} finally {
ffmpeg.destroy();
}
int size = res.size();
String[] ret = new String[size];
for (int i = 0; i < size; i++) {
ret[i] = (String) res.get(i);
}
return ret;
}
public String[] getSupportedEncodingFormats() throws EncoderException {
ArrayList res = new ArrayList();
FFMPEGExecutor ffmpeg = locator.createExecutor();
ffmpeg.addArgument("-formats");
try {
ffmpeg.execute();
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getInputStream()));
String line;
boolean evaluate = false;
while ((line = reader.readLine()) != null) {
if (line.trim().length() == 0) {
continue;
}
if (evaluate) {
Matcher matcher = FORMAT_PATTERN.matcher(line);
if (matcher.matches()) {
String encoderFlag = matcher.group(2);
if ("E".equals(encoderFlag)) {
String aux = matcher.group(3);
StringTokenizer st = new StringTokenizer(aux, ",");
while (st.hasMoreTokens()) {
String token = st.nextToken().trim();
if (!res.contains(token)) {
res.add(token);
}
}
}
} else {
break;
}
} else if (line.trim().equals("File formats:")) {
evaluate = true;
}
}
} catch (IOException e) {
throw new EncoderException(e);
} finally {
ffmpeg.destroy();
}
int size = res.size();
String[] ret = new String[size];
for (int i = 0; i < size; i++) {
ret[i] = (String) res.get(i);
}
return ret;
}
public String[] getSupportedDecodingFormats() throws EncoderException {
ArrayList res = new ArrayList();
FFMPEGExecutor ffmpeg = locator.createExecutor();
ffmpeg.addArgument("-formats");
try {
ffmpeg.execute();
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getInputStream()));
String line;
boolean evaluate = false;
while ((line = reader.readLine()) != null) {
if (line.trim().length() == 0) {
continue;
}
if (evaluate) {
Matcher matcher = FORMAT_PATTERN.matcher(line);
if (matcher.matches()) {
String decoderFlag = matcher.group(1);
if ("D".equals(decoderFlag)) {
String aux = matcher.group(3);
StringTokenizer st = new StringTokenizer(aux, ",");
while (st.hasMoreTokens()) {
String token = st.nextToken().trim();
if (!res.contains(token)) {
res.add(token);
}
}
}
} else {
break;
}
} else if (line.trim().equals("File formats:")) {
evaluate = true;
}
}
} catch (IOException e) {
throw new EncoderException(e);
} finally {
ffmpeg.destroy();
}
int size = res.size();
String[] ret = new String[size];
for (int i = 0; i < size; i++) {
ret[i] = (String) res.get(i);
}
return ret;
}
public MultimediaInfo getInfo(File source) throws InputFormatException,
EncoderException {
FFMPEGExecutor ffmpeg = locator.createExecutor();
ffmpeg.addArgument("-i");
ffmpeg.addArgument(source.getAbsolutePath());
try {
ffmpeg.execute();
} catch (IOException e) {
throw new EncoderException(e);
}
try {
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getErrorStream()));
return parseMultimediaInfo(source, reader);
} finally {
ffmpeg.destroy();
}
}
private MultimediaInfo parseMultimediaInfo(File source,
RBufferedReader reader) throws InputFormatException,
EncoderException {
Pattern p1 = Pattern.compile("^\\s*Input #0, (\\w+).+$\\s*",
Pattern.CASE_INSENSITIVE);
Pattern p2 = Pattern.compile(
"^\\s*Duration: (\\d\\d):(\\d\\d):(\\d\\d)\\.(\\d).*$",
Pattern.CASE_INSENSITIVE);
Pattern p3 = Pattern.compile(
"^\\s*Stream #\\S+: ((?:Audio)|(?:Video)|(?:Data)): (.*)\\s*$",
Pattern.CASE_INSENSITIVE);
MultimediaInfo info = null;
try {
int step = 0;
while (true) {
String line = reader.readLine();
if (line == null) {
break;
}
if (step == 0) {
String token = source.getAbsolutePath() + ": ";
if (line.startsWith(token)) {
String message = line.substring(token.length());
throw new InputFormatException(message);
}
Matcher m = p1.matcher(line);
if (m.matches()) {
String format = m.group(1);
info = new MultimediaInfo();
info.setFormat(format);
step++;
}
} else if (step == 1) {
Matcher m = p2.matcher(line);
if (m.matches()) {
long hours = Integer.parseInt(m.group(1));
long minutes = Integer.parseInt(m.group(2));
long seconds = Integer.parseInt(m.group(3));
long dec = Integer.parseInt(m.group(4));
long duration = (dec * 100L) + (seconds * 1000L)
+ (minutes * 60L * 1000L)
+ (hours * 60L * 60L * 1000L);
info.setDuration(duration);
step++;
} else {
step = 3;
}
} else if (step == 2) {
Matcher m = p3.matcher(line);
if (m.matches()) {
String type = m.group(1);
String specs = m.group(2);
if ("Video".equalsIgnoreCase(type)) {
VideoInfo video = new VideoInfo();
StringTokenizer st = new StringTokenizer(specs, ",");
for (int i = 0; st.hasMoreTokens(); i++) {
String token = st.nextToken().trim();
if (i == 0) {
video.setDecoder(token);
} else {
boolean parsed = false;
// Video size.
Matcher m2 = SIZE_PATTERN.matcher(token);
if (!parsed && m2.find()) {
int width = Integer.parseInt(m2
.group(1));
int height = Integer.parseInt(m2
.group(2));
video.setSize(new VideoSize(width,
height));
parsed = true;
}
// Frame rate.
m2 = FRAME_RATE_PATTERN.matcher(token);
if (!parsed && m2.find()) {
try {
float frameRate = Float
.parseFloat(m2.group(1));
video.setFrameRate(frameRate);
} catch (NumberFormatException e) {
;
}
parsed = true;
}
// Bit rate.
m2 = BIT_RATE_PATTERN.matcher(token);
if (!parsed && m2.find()) {
int bitRate = Integer.parseInt(m2
.group(1));
video.setBitRate(bitRate);
parsed = true;
}
}
}
info.setVideo(video);
} else if ("Audio".equalsIgnoreCase(type)) {
AudioInfo audio = new AudioInfo();
StringTokenizer st = new StringTokenizer(specs, ",");
for (int i = 0; st.hasMoreTokens(); i++) {
String token = st.nextToken().trim();
if (i == 0) {
audio.setDecoder(token);
} else {
boolean parsed = false;
// Sampling rate.
Matcher m2 = SAMPLING_RATE_PATTERN
.matcher(token);
if (!parsed && m2.find()) {
int samplingRate = Integer.parseInt(m2
.group(1));
audio.setSamplingRate(samplingRate);
parsed = true;
}
// Channels.
m2 = CHANNELS_PATTERN.matcher(token);
if (!parsed && m2.find()) {
String ms = m2.group(1);
if ("mono".equalsIgnoreCase(ms)) {
audio.setChannels(1);
} else if ("stereo"
.equalsIgnoreCase(ms)) {
audio.setChannels(2);
}
parsed = true;
}
// Bit rate.
m2 = BIT_RATE_PATTERN.matcher(token);
if (!parsed && m2.find()) {
int bitRate = Integer.parseInt(m2
.group(1));
audio.setBitRate(bitRate);
parsed = true;
}
}
}
info.setAudio(audio);
}
} else {
step = 3;
}
}
if (step == 3) {
reader.reinsertLine(line);
break;
}
}
} catch (IOException e) {
throw new EncoderException(e);
}
if (info == null) {
throw new InputFormatException();
}
return info;
}
private Hashtable parseProgressInfoLine(String line) {
Hashtable table = null;
Matcher m = PROGRESS_INFO_PATTERN.matcher(line);
while (m.find()) {
if (table == null) {
table = new Hashtable();
}
String key = m.group(1);
String value = m.group(2);
table.put(key, value);
}
return table;
}
public void encode(File source, File target, EncodingAttributes attributes)
throws IllegalArgumentException, InputFormatException,
EncoderException {
encode(source, target, attributes, null);
}
public void encode(File source, File target, EncodingAttributes attributes,
EncoderProgressListener listener) throws IllegalArgumentException,
InputFormatException, EncoderException {
String formatAttribute = attributes.getFormat();
Float offsetAttribute = attributes.getOffset();
Float durationAttribute = attributes.getDuration();
AudioAttributes audioAttributes = attributes.getAudioAttributes();
VideoAttributes videoAttributes = attributes.getVideoAttributes();
if (audioAttributes == null && videoAttributes == null) {
throw new IllegalArgumentException(
"Both audio and video attributes are null");
}
target = target.getAbsoluteFile();
target.getParentFile().mkdirs();
FFMPEGExecutor ffmpeg = locator.createExecutor();
if (offsetAttribute != null) {
ffmpeg.addArgument("-ss");
ffmpeg.addArgument(String.valueOf(offsetAttribute.floatValue()));
}
ffmpeg.addArgument("-i");
ffmpeg.addArgument(source.getAbsolutePath());
if (durationAttribute != null) {
ffmpeg.addArgument("-t");
ffmpeg.addArgument(String.valueOf(durationAttribute.floatValue()));
}
if (videoAttributes == null) {
ffmpeg.addArgument("-vn");
} else {
String codec = videoAttributes.getCodec();
if (codec != null) {
ffmpeg.addArgument("-vcodec");
ffmpeg.addArgument(codec);
}
String tag = videoAttributes.getTag();
if (tag != null) {
ffmpeg.addArgument("-vtag");
ffmpeg.addArgument(tag);
}
Integer bitRate = videoAttributes.getBitRate();
if (bitRate != null) {
ffmpeg.addArgument("-b");
ffmpeg.addArgument(String.valueOf(bitRate.intValue()));
}
Integer frameRate = videoAttributes.getFrameRate();
if (frameRate != null) {
ffmpeg.addArgument("-r");
ffmpeg.addArgument(String.valueOf(frameRate.intValue()));
}
VideoSize size = videoAttributes.getSize();
if (size != null) {
ffmpeg.addArgument("-s");
ffmpeg.addArgument(String.valueOf(size.getWidth()) + "x"
+ String.valueOf(size.getHeight()));
}
}
if (audioAttributes == null) {
ffmpeg.addArgument("-an");
} else {
String codec = audioAttributes.getCodec();
if (codec != null) {
ffmpeg.addArgument("-acodec");
ffmpeg.addArgument(codec);
}
Integer bitRate = audioAttributes.getBitRate();
if (bitRate != null) {
ffmpeg.addArgument("-ab");
ffmpeg.addArgument(String.valueOf(bitRate.intValue()));
}
Integer channels = audioAttributes.getChannels();
if (channels != null) {
ffmpeg.addArgument("-ac");
ffmpeg.addArgument(String.valueOf(channels.intValue()));
}
Integer samplingRate = audioAttributes.getSamplingRate();
if (samplingRate != null) {
ffmpeg.addArgument("-ar");
ffmpeg.addArgument(String.valueOf(samplingRate.intValue()));
}
Integer volume = audioAttributes.getVolume();
if (volume != null) {
ffmpeg.addArgument("-vol");
ffmpeg.addArgument(String.valueOf(volume.intValue()));
}
}
ffmpeg.addArgument("-f");
ffmpeg.addArgument(formatAttribute);
ffmpeg.addArgument("-y");
ffmpeg.addArgument(target.getAbsolutePath());
try {
ffmpeg.execute();
} catch (IOException e) {
throw new EncoderException(e);
}
try {
String lastWarning = null;
long duration;
long progress = 0;
RBufferedReader reader = null;
reader = new RBufferedReader(new InputStreamReader(ffmpeg
.getErrorStream()));
MultimediaInfo info = parseMultimediaInfo(source, reader);
if (durationAttribute != null) {
duration = (long) Math
.round((durationAttribute.floatValue() * 1000L));
} else {
duration = info.getDuration();
if (offsetAttribute != null) {
duration -= (long) Math
.round((offsetAttribute.floatValue() * 1000L));
}
}
if (listener != null) {
listener.sourceInfo(info);
}
int step = 0;
String line;
while ((line = reader.readLine()) != null) {
if (step == 0) {
if (line.startsWith("WARNING: ")) {
if (listener != null) {
listener.message(line);
}
} else if (!line.startsWith("Output #0")) {
throw new EncoderException(line);
} else {
step++;
}
} else if (step == 1) {
if (!line.startsWith(" ")) {
step++;
}
}
if (step == 2) {
if (!line.startsWith("Stream mapping:")) {
throw new EncoderException(line);
} else {
step++;
}
} else if (step == 3) {
if (!line.startsWith(" ")) {
step++;
}
}
if (step == 4) {
line = line.trim();
if (line.length() > 0) {
Hashtable table = parseProgressInfoLine(line);
if (table == null) {
if (listener != null) {
listener.message(line);
}
lastWarning = line;
} else {
if (listener != null) {
String time = (String) table.get("time");
if (time != null) {
int dot = time.indexOf('.');
if (dot > 0 && dot == time.length() - 2
&& duration > 0) {
String p1 = time.substring(0, dot);
String p2 = time.substring(dot + 1);
try {
long i1 = Long.parseLong(p1);
long i2 = Long.parseLong(p2);
progress = (i1 * 1000L)
+ (i2 * 100L);
int perm = (int) Math
.round((double) (progress * 1000L)
/ (double) duration);
if (perm > 1000) {
perm = 1000;kMDItemAudioEncodingApplication = "Lavf57.26.100"
}
listener.progress(perm);
} catch (NumberFormatException e) {
;
}
}
}
}
lastWarning = null;
}
}
}
}
if (lastWarning != null) {
if (!SUCCESS_PATTERN.matcher(lastWarning).matches()) {
throw new EncoderException(lastWarning);
}
}
} catch (IOException e) {
throw new EncoderException(e);
} finally {
ffmpeg.destroy();
}
}
} -
Encoding H.264 CBR videos with FFmpeg
27 août 2015, par CornstalksI’m trying to encode a video with ffmpeg into H.264 (via the libx264 library) with a constant bit rate. I know, I know, VBR is often preferred, but for this specific job I’m required to use CBR (just as long as it’s so many kilobytes per second ; it doesn’t have to be an exact kilobytes per frame, afaik). My sample video I’m using to test is from here : http://a1408.g.akamai.net/5/1408/1388/2005110403/1a1a1ad948be278cff2d96046ad90768d848b41947aa1986/sample_iTunes.mov.zip (it comes from http://support.apple.com/kb/HT1425)
I can get a constant bit rate when encoding the video with MPEG-4 Video (using the commands
ffmpeg -i sample_iTunes.mov -b 819968 -minrate 819968 -maxrate 819968 out.mov), and the bit rate is as expected. Reading the video’s specs via the QuickTime Inspector, it’s got a data rate of 844.94 kbit/s. Cool.However, when I change the codec to libx264, it seems to completely ignore my bitrate requests ! The command I’m trying is "
ffmpeg -i sample_iTunes.mov -vcodec libx264 -vpre medium -b 819968 -vb 819968 -minrate 819968 -maxrate 819968 -bufsize 400000 test.mov". But when I check the video’s specs via the QuickTime Inspector, it’s got a data rate of 254.74 kbit/s. WTF ? That’s not even close !I’ve tried changing so many parameters and adding tons of different things, and I’ve spent 2 days googling this, but I can’t seem to get it to work. If I encode the video with the MainConcept H.264 encoder, I can get a constant bitrate, but I need this to work with ffmpeg.
If someone can help me figure out how to do CBR H.264 encoding with FFmpeg, I will love you forever !
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