我正在尝试将一组图像转换为mp4视频。
但我在创建视频时遇到了一些问题，不确定我的代码是否正确以创建有效的mp4视频。
当我使用FFmpeg处理结果视频时，遇到了很多问题。出现了很多错误和警告，好像我的视频没有被正确编码。
我是不是忘了什么或犯了错误？提前感谢您的帮助。
代码：
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.media.MediaMuxer;
import android.util.Log;
import android.view.Surface;
import java.nio.ByteBuffer;
public class ImageVideoConverter {
private static final String TAG = "ImageVideoConverter";
private static final String OUTPUT_MIME = MediaFormat.MIMETYPE_VIDEO_AVC;
private static final int TIMEOUT_USEC = 10000;
private static final int frameRate = 30;
private static final int bitrate = 700000;
private static final int keyFrameInternal = 1;
public static void convertImageToVideo(String filePath,
float duration,
int width,
int height,
final String videoFilePath ) {
int nbFrames = (int)(duration * (float)frameRate) + 1;
MediaMuxer muxer = null;
MediaCodec codec = null;
boolean muxerStarted = false;
boolean codecStarted = false;
int videoTrackIndex = -1;
try {
MediaFormat mediaFormat = MediaFormat.createVideoFormat(OUTPUT_MIME, width, height);
muxer = new MediaMuxer(videoFilePath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
codec = MediaCodec.createEncoderByType(OUTPUT_MIME);
mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, bitrate);
mediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, frameRate);
mediaFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
mediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, keyFrameInternal);
try {
codec.configure(mediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
}
catch(Exception ce) {
Log.e(TAG, ce.getMessage());
}
Surface surface = codec.createInputSurface();
codec.start();
codecStarted = true;
ByteBuffer[] outputBuffers = codec.getOutputBuffers();
int outputBufferIndex;
MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
boolean outputDone = false;
int nbEncoded = 0;
Bitmap frame = getBitmapFromImage(filePath, width, height);
Canvas canvas = surface.lockCanvas(new Rect(0,0, width, height));
canvas.drawBitmap(frame, 0, 0, new Paint());
surface.unlockCanvasAndPost(canvas);
while (!outputDone) {
canvas = surface.lockCanvas(new Rect(0,0, 0, 0));
surface.unlockCanvasAndPost(canvas);
outputBufferIndex = codec.dequeueOutputBuffer(info, TIMEOUT_USEC);
if (outputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER) {
// no output available yet
Log.d(TAG, "no output from encoder available");
} else if (outputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
// not expected for an encoder
outputBuffers = codec.getOutputBuffers();
Log.d(TAG, "encoder output buffers changed");
} else if (outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
if(muxerStarted)
throwException("format changed twice");
MediaFormat newFormat = codec.getOutputFormat();
videoTrackIndex = muxer.addTrack(newFormat);
muxer.start();
muxerStarted = true;
} else if (outputBufferIndex < 0) {
throwException("unexpected result from encoder.dequeueOutputBuffer: " + outputBufferIndex);
} else { // encoderStatus >= 0
ByteBuffer encodedData = outputBuffers[outputBufferIndex];
if (encodedData == null) {
throwException("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 (!muxerStarted)
throwException("muxer hasn't started");
info.presentationTimeUs = computePresentationTime(nbEncoded, frameRate);
if(videoTrackIndex == -1)
throwException("video track not set yet");
muxer.writeSampleData(videoTrackIndex, encodedData, info);
nbEncoded++;
if(nbEncoded == nbFrames)
outputDone = true;
}
// It's usually necessary to adjust the ByteBuffer values to match BufferInfo.
codec.releaseOutputBuffer(outputBufferIndex, false);
}
}
if (codec != null) {
if (codecStarted) {codec.stop();}
codec.release();
}
if (muxer != null) {
if (muxerStarted) {muxer.stop();}
muxer.release();
}
} catch (Exception e) {
Log.e(TAG, "Encoding exception: " + e.toString());
}
}
private static long computePresentationTime(int frameIndex, int frameRate) {
return frameIndex * 1000000 / frameRate;
}
private static Bitmap getBitmapFromImage(String inputFilePath, int width, int height) {
Bitmap bitmap = decodeSampledBitmapFromFile(inputFilePath, width, height);
if(bitmap.getWidth() != width || bitmap.getHeight() != height) {
Bitmap scaled = Bitmap.createScaledBitmap(bitmap, width, height, false);
bitmap.recycle();
return scaled;
}
else {
return bitmap;
}
}
private static Bitmap decodeSampledBitmapFromFile(String filePath,
int reqWidth,
int reqHeight) {
final BitmapFactory.Options options = new BitmapFactory.Options();
// Calculate inSampleSize
// First decode with inJustDecodeBounds=true to check dimensions
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, options);
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
options.inPreferredConfig = Bitmap.Config.RGB_565;
options.inDither = true;
return BitmapFactory.decodeFile(filePath, options);
}
private static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
while ((halfHeight / inSampleSize) > reqHeight
&& (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
private static void throwException(String exp) {
throw new RuntimeException(exp);
}
}
ffprobe -show_frames input.mp4命令来查看样本和关键帧间隔之间的差异。您可以将结果与您的逻辑进行比较。 - Endre Börcsök