使用 FFMPEG 从 Android 流式传输图像
Stream image from Android with FFMPEG
我目前正在从外部源接收图像作为字节数组，我想通过 ffmpeg 将其作为原始视频格式发送到流 URL，我有一个接收 RTSP 流的 RTSP 服务器(a similar unanswered question)。但是，我没有在 Java 中使用过 FFMPEG，所以我找不到有关如何操作的示例。我有一个将图像字节复制到字节数组的回调，如下所示：
public class MainActivity extends Activity {
final String rtmp_url = "rtmp://192.168.0.12:1935/live/test";
private int PREVIEW_WIDTH = 384;
private int PREVIEW_HEIGHT = 292;
private String TAG = "MainActivity";
String ffmpeg = Loader.load(org.bytedeco.ffmpeg.ffmpeg.class);
final String command[] = {ffmpeg,
"-y", //Add "-re" for simulated readtime streaming.
"-f", "rawvideo",
"-vcodec", "rawvideo",
"-pix_fmt", "bgr24",
"-s", (Integer.toString(PREVIEW_WIDTH) + "x" + Integer.toString(PREVIEW_HEIGHT)),
"-r", "10",
"-i", "pipe:",
"-c:v", "libx264",
"-pix_fmt", "yuv420p",
"-preset", "ultrafast",
"-f", "flv",
rtmp_url};
private UVCCamera mUVCCamera;
public void handleStartPreview(Object surface) throws InterruptedException, IOException {
Log.e(TAG, "handleStartPreview:mUVCCamera" + mUVCCamera + " mIsPreviewing:");
if ((mUVCCamera == null)) return;
Log.e(TAG, "handleStartPreview2 ");
try {
mUVCCamera.setPreviewSize(mWidth, mHeight, 1, 26, 0, UVCCamera.DEFAULT_BANDWIDTH, 0);
Log.e(TAG, "handleStartPreview3 mWidth: " + mWidth + "mHeight:" + mHeight);
} catch (IllegalArgumentException e) {
try {
// fallback to YUV mode
mUVCCamera.setPreviewSize(mWidth, mHeight, 1, 26, UVCCamera.DEFAULT_PREVIEW_MODE, UVCCamera.DEFAULT_BANDWIDTH, 0);
Log.e(TAG, "handleStartPreview4");
} catch (IllegalArgumentException e1) {
callOnError(e1);
return;
}
}
Log.e(TAG, "handleStartPreview: startPreview1");
int result = mUVCCamera.startPreview();
mUVCCamera.setFrameCallback(mIFrameCallback, UVCCamera.PIXEL_FORMAT_RGBX);
mUVCCamera.startCapture();
Toast.makeText(MainActivity.this,"Camera Started",Toast.LENGTH_SHORT).show();
ProcessBuilder pb = new ProcessBuilder(command);
pb.redirectErrorStream(true);
Process process = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
OutputStream writer = process.getOutputStream();
byte img[] = new byte[192*108*3];
for (int i = 0; i < 10; i++)
{
for (int y = 0; y < 108; y++)
{
for (int x = 0; x < 192; x++)
{
byte r = (byte)((x * y + i) % 255);
byte g = (byte)((x * y + i*10) % 255);
byte b = (byte)((x * y + i*20) % 255);
img[(y*192 + x)*3] = b;
img[(y*192 + x)*3+1] = g;
img[(y*192 + x)*3+2] = r;
}
}
writer.write(img);
}
writer.close();
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
process.waitFor();
}
public static void buildRawFrame(Mat img, int i)
{
int p = img.cols() / 60;
img.setTo(new Scalar(60, 60, 60));
String text = Integer.toString(i+1);
int font = Imgproc.FONT_HERSHEY_SIMPLEX;
Point pos = new Point(img.cols()/2-p*10*(text.length()), img.rows()/2+p*10);
Imgproc.putText(img, text, pos, font, p, new Scalar(255, 30, 30), p*2); //Blue number
}
另外：Android Camera Capture using FFmpeg
使用 ffmpeg 从原生 android 相机逐帧捕捉，而不是通过 RTMP 推送，他们过去常常生成视频文件作为输出。虽然没有告知图像是如何通过ffmpeg传递的。
frameData 是我的字节数组，我想知道如何使用 ProcessBuilder 编写必要的 ffmpeg 命令以使用 ffmpeg 通过 RTSP 为给定的 URL.
发送图像
我正在尝试做的一个例子，在 Python 3 中，我可以通过以下方式轻松做到：
import cv2
import numpy as np
import socket
import sys
import pickle
import struct
import subprocess
fps = 25
width = 224
height = 224
rtmp_url = 'rtmp://192.168.0.13:1935/live/test'
command = ['ffmpeg',
'-y',
'-f', 'rawvideo',
'-vcodec', 'rawvideo',
'-pix_fmt', 'bgr24',
'-s', "{}x{}".format(width, height),
'-r', str(fps),
'-i', '-',
'-c:v', 'libx264',
'-pix_fmt', 'yuv420p',
'-preset', 'ultrafast',
'-f', 'flv',
rtmp_url]
p = subprocess.Popen(command, stdin=subprocess.PIPE)
while(True):
frame = np.random.randint([255], size=(224, 224, 3))
frame = frame.astype(np.uint8)
p.stdin.write(frame.tobytes())
我想在 Android
做同样的事情
更新：虽然我可以在 Netbeans 上重现@Rotem 的回答，但在 Android 中，我在尝试执行 pb.start() 时收到 NullPointer 异常错误。
Process: com.infiRay.XthermMini, PID: 32089
java.lang.NullPointerException
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012)
at com.infiRay.XthermMini.MainActivity.handleStartPreview(MainActivity.java:512)
at com.infiRay.XthermMini.MainActivity.startPreview(MainActivity.java:563)
at com.infiRay.XthermMini.MainActivity.access00(MainActivity.java:49)
at com.infiRay.XthermMini.MainActivity.onConnect(MainActivity.java:316)
at com.serenegiant.usb.USBMonitor.run(USBMonitor.java:620)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.os.HandlerThread.run(HandlerThread.java:67)
2022-06-02 11:47:20.300 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.304 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.304 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.308 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.312 32089-32089/com.infiRay.XthermMini E/MainActivity: onPause:
2022-06-02 11:47:20.314 32089-32581/com.infiRay.XthermMini I/Process: Sending signal. PID: 32089 SIG: 9
这是一个类似于 Python 代码的 JAVA 实现：
该示例将原始视频帧（字节数组）写入 FFmpeg 的标准输入管道 sub-process:
_____________ ___________ ________
| JAVA byte | | | | |
| Array | stdin | FFmpeg | | Output |
| BGR (format)| --------> | process | -------------> | stream |
|_____________| raw frame |___________| encoded video |________|
主要阶段：
初始化FFmpeg命令参数：
final String command[] = {"ffmpeg", "-f", "rawvideo", ...}
创建 ProcessBuilder 执行 FFmpeg 作为 sub-process:
ProcessBuilder pb = new ProcessBuilder(command);
重定向 stderr（读取 FFmpeg 消息所需），没有它，sub-process 停止：
pb.redirectErrorStream(true);
启动 FFmpeg sub-process，并创建 BufferedReader:
Process process = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
创建 OutputStream 用于写入 FFmpeg 的标准输入管道 sub-process:
OutputStream writer = process.getOutputStream();
循环将原始视频帧写入 FFmpeg sub-process 的标准输入管道：
byte img[] = new byte[width*height*3];
for (int i = 0; i < n_frmaes; i++)
{
//Fill img with pixel data
...
writer.write(img);
}
关闭stdin，读取并打印stderr内容，等待sub-process完成：
writer.close();
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
process.waitFor();
代码示例：
以下代码示例将 10 个大小为 192x108 的原始视频帧写入 FFmpeg。
我们不是将流式传输到 RTMP，而是将结果写入 test.flv 文件（用于测试）。
该示例使用硬编码字符串和数字（为简单起见）。
注：
代码示例假设 FFmpeg 可执行文件在执行路径中。
package myproject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
public class FfmpegVideoWriter {
public static void main(String[] args) throws IOException, InterruptedException {
final String rtmp_url = "test.flv"; //Set output file (instead of output URL) for testing.
final String command[] = {"ffmpeg",
"-y", //Add "-re" for simulated readtime streaming.
"-f", "rawvideo",
"-vcodec", "rawvideo",
"-pix_fmt", "bgr24",
"-s", "192x108",
"-r", "10",
"-i", "pipe:",
"-c:v", "libx264",
"-pix_fmt", "yuv420p",
"-preset", "ultrafast",
"-f", "flv",
rtmp_url};
//
ProcessBuilder pb = new ProcessBuilder(command); //Create ProcessBuilder
pb.redirectErrorStream(true); //Redirect stderr
Process process = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
//Create OutputStream for writing to stdin pipe of FFmpeg sub-process.
OutputStream writer = process.getOutputStream();
byte img[] = new byte[192*108*3]; //Dummy image
//Write 10 video frames to stdin pipe of FFmpeg sub-process
for (int i = 0; i < 10; i++)
{
//Fill image with some arbitrary pixel values
for (int y = 0; y < 108; y++)
{
for (int x = 0; x < 192; x++)
{
//Arbitrary RGB values:
byte r = (byte)((x * y + i) % 255); //Red component
byte g = (byte)((x * y + i*10) % 255); //Green component
byte b = (byte)((x * y + i*20) % 255); //Blue component
img[(y*192 + x)*3] = b;
img[(y*192 + x)*3+1] = g;
img[(y*192 + x)*3+2] = r;
}
}
writer.write(img); //Write img to FFmpeg
}
writer.close(); //Close stdin pipe.
//Read and print stderr content
//Note: there may be cases when FFmpeg keeps printing messages, so it may not be the best solution to empty the buffer only at the end.
//We may consider adding an argument `-loglevel error` for reducing verbosity.
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
process.waitFor();
}
}
该代码已在我的 PC 上进行了测试（使用 Windows 10），但我不确定它是否适用于 Android...
上面的示例简单而通用，在您的情况下，您可以使用 rgba 像素格式并在 onFrame 方法中写入 FrameData。
示例视频帧（“任意像素值”）：
更新：
以下代码示例使用 JavaCV - 将 Mat 数据写入 FFmpeg：
package myproject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.Scalar;
import org.opencv.core.Point;
import org.opencv.imgproc.Imgproc;
public class FfmpegVideoWriter {
static { System.loadLibrary(Core.NATIVE_LIBRARY_NAME); }
//Build synthetic "raw BGR" image for testing
public static void buildRawFrame(Mat img, int i)
{
int p = img.cols() / 60; //Used as font size factor.
img.setTo(new Scalar(60, 60, 60)); //Fill image with dark gray color
String text = Integer.toString(i+1);
int font = Imgproc.FONT_HERSHEY_SIMPLEX;
Point pos = new Point(img.cols()/2-p*10*(text.length()), img.rows()/2+p*10);
Imgproc.putText(img, text, pos, font, p, new Scalar(255, 30, 30), p*2); //Blue number
}
public static void main(String[] args) throws IOException, InterruptedException {
final int cols = 192;
final int rows = 108;
final String rtmp_url = "test.flv"; //Set output file (instead of output URL) for testing.
final String command[] = {"ffmpeg",
"-y", //Add "-re" for simulated readtime streaming.
"-f", "rawvideo",
"-vcodec", "rawvideo",
"-pix_fmt", "bgr24",
"-s", (Integer.toString(cols) + "x" + Integer.toString(rows)),
"-r", "10",
"-i", "pipe:",
"-c:v", "libx264",
"-pix_fmt", "yuv420p",
"-preset", "ultrafast",
"-f", "flv",
rtmp_url};
//
ProcessBuilder pb = new ProcessBuilder(command); //Create ProcessBuilder
pb.redirectErrorStream(true); //Redirect stderr
Process process = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
//Create OutputStream for writing to stdin pipe of FFmpeg sub-process.
OutputStream writer = process.getOutputStream();
//Dummy image (BGR pixel format).
Mat img = new Mat(rows, cols, CvType.CV_8UC3, Scalar.all(0));
byte buffer[] = new byte[cols*rows*3]; //Byte array for storing img data
//Write 10 video frames to stdin pipe of FFmpeg sub-process
for (int i = 0; i < 10; i++)
{
buildRawFrame(img, i); //Build image with blue frame counter.
img.get(0, 0, buffer); //Copy img data to buffer (not sure if this is the best solution).
writer.write(buffer); //Write buffer (raw video frame as byte array) to FFmpeg
}
writer.close(); //Close stdin pipe.
//Read and print stderr content
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
process.waitFor();
}
}
示例输出帧：
我目前正在从外部源接收图像作为字节数组，我想通过 ffmpeg 将其作为原始视频格式发送到流 URL，我有一个接收 RTSP 流的 RTSP 服务器(a similar unanswered question)。但是，我没有在 Java 中使用过 FFMPEG，所以我找不到有关如何操作的示例。我有一个将图像字节复制到字节数组的回调，如下所示：
public class MainActivity extends Activity {
final String rtmp_url = "rtmp://192.168.0.12:1935/live/test";
private int PREVIEW_WIDTH = 384;
private int PREVIEW_HEIGHT = 292;
private String TAG = "MainActivity";
String ffmpeg = Loader.load(org.bytedeco.ffmpeg.ffmpeg.class);
final String command[] = {ffmpeg,
"-y", //Add "-re" for simulated readtime streaming.
"-f", "rawvideo",
"-vcodec", "rawvideo",
"-pix_fmt", "bgr24",
"-s", (Integer.toString(PREVIEW_WIDTH) + "x" + Integer.toString(PREVIEW_HEIGHT)),
"-r", "10",
"-i", "pipe:",
"-c:v", "libx264",
"-pix_fmt", "yuv420p",
"-preset", "ultrafast",
"-f", "flv",
rtmp_url};
private UVCCamera mUVCCamera;
public void handleStartPreview(Object surface) throws InterruptedException, IOException {
Log.e(TAG, "handleStartPreview:mUVCCamera" + mUVCCamera + " mIsPreviewing:");
if ((mUVCCamera == null)) return;
Log.e(TAG, "handleStartPreview2 ");
try {
mUVCCamera.setPreviewSize(mWidth, mHeight, 1, 26, 0, UVCCamera.DEFAULT_BANDWIDTH, 0);
Log.e(TAG, "handleStartPreview3 mWidth: " + mWidth + "mHeight:" + mHeight);
} catch (IllegalArgumentException e) {
try {
// fallback to YUV mode
mUVCCamera.setPreviewSize(mWidth, mHeight, 1, 26, UVCCamera.DEFAULT_PREVIEW_MODE, UVCCamera.DEFAULT_BANDWIDTH, 0);
Log.e(TAG, "handleStartPreview4");
} catch (IllegalArgumentException e1) {
callOnError(e1);
return;
}
}
Log.e(TAG, "handleStartPreview: startPreview1");
int result = mUVCCamera.startPreview();
mUVCCamera.setFrameCallback(mIFrameCallback, UVCCamera.PIXEL_FORMAT_RGBX);
mUVCCamera.startCapture();
Toast.makeText(MainActivity.this,"Camera Started",Toast.LENGTH_SHORT).show();
ProcessBuilder pb = new ProcessBuilder(command);
pb.redirectErrorStream(true);
Process process = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
OutputStream writer = process.getOutputStream();
byte img[] = new byte[192*108*3];
for (int i = 0; i < 10; i++)
{
for (int y = 0; y < 108; y++)
{
for (int x = 0; x < 192; x++)
{
byte r = (byte)((x * y + i) % 255);
byte g = (byte)((x * y + i*10) % 255);
byte b = (byte)((x * y + i*20) % 255);
img[(y*192 + x)*3] = b;
img[(y*192 + x)*3+1] = g;
img[(y*192 + x)*3+2] = r;
}
}
writer.write(img);
}
writer.close();
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
process.waitFor();
}
public static void buildRawFrame(Mat img, int i)
{
int p = img.cols() / 60;
img.setTo(new Scalar(60, 60, 60));
String text = Integer.toString(i+1);
int font = Imgproc.FONT_HERSHEY_SIMPLEX;
Point pos = new Point(img.cols()/2-p*10*(text.length()), img.rows()/2+p*10);
Imgproc.putText(img, text, pos, font, p, new Scalar(255, 30, 30), p*2); //Blue number
}
另外：Android Camera Capture using FFmpeg
使用 ffmpeg 从原生 android 相机逐帧捕捉，而不是通过 RTMP 推送，他们过去常常生成视频文件作为输出。虽然没有告知图像是如何通过ffmpeg传递的。
frameData 是我的字节数组，我想知道如何使用 ProcessBuilder 编写必要的 ffmpeg 命令以使用 ffmpeg 通过 RTSP 为给定的 URL.
发送图像我正在尝试做的一个例子，在 Python 3 中，我可以通过以下方式轻松做到：
import cv2
import numpy as np
import socket
import sys
import pickle
import struct
import subprocess
fps = 25
width = 224
height = 224
rtmp_url = 'rtmp://192.168.0.13:1935/live/test'
command = ['ffmpeg',
'-y',
'-f', 'rawvideo',
'-vcodec', 'rawvideo',
'-pix_fmt', 'bgr24',
'-s', "{}x{}".format(width, height),
'-r', str(fps),
'-i', '-',
'-c:v', 'libx264',
'-pix_fmt', 'yuv420p',
'-preset', 'ultrafast',
'-f', 'flv',
rtmp_url]
p = subprocess.Popen(command, stdin=subprocess.PIPE)
while(True):
frame = np.random.randint([255], size=(224, 224, 3))
frame = frame.astype(np.uint8)
p.stdin.write(frame.tobytes())
我想在 Android
做同样的事情更新：虽然我可以在 Netbeans 上重现@Rotem 的回答，但在 Android 中，我在尝试执行 pb.start() 时收到 NullPointer 异常错误。
Process: com.infiRay.XthermMini, PID: 32089
java.lang.NullPointerException
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012)
at com.infiRay.XthermMini.MainActivity.handleStartPreview(MainActivity.java:512)
at com.infiRay.XthermMini.MainActivity.startPreview(MainActivity.java:563)
at com.infiRay.XthermMini.MainActivity.access00(MainActivity.java:49)
at com.infiRay.XthermMini.MainActivity.onConnect(MainActivity.java:316)
at com.serenegiant.usb.USBMonitor.run(USBMonitor.java:620)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.os.HandlerThread.run(HandlerThread.java:67)
2022-06-02 11:47:20.300 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.304 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.304 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.308 32089-1049/com.infiRay.XthermMini E/libUVCCamera: [1049*UVCPreviewIR.cpp:505:uvc_preview_frame_callback]:receive err data
2022-06-02 11:47:20.312 32089-32089/com.infiRay.XthermMini E/MainActivity: onPause:
2022-06-02 11:47:20.314 32089-32581/com.infiRay.XthermMini I/Process: Sending signal. PID: 32089 SIG: 9
这是一个类似于 Python 代码的 JAVA 实现：
该示例将原始视频帧（字节数组）写入 FFmpeg 的标准输入管道 sub-process:
_____________ ___________ ________
| JAVA byte | | | | |
| Array | stdin | FFmpeg | | Output |
| BGR (format)| --------> | process | -------------> | stream |
|_____________| raw frame |___________| encoded video |________|
主要阶段：
初始化FFmpeg命令参数：
final String command[] = {"ffmpeg", "-f", "rawvideo", ...}创建
ProcessBuilder执行 FFmpeg 作为 sub-process:ProcessBuilder pb = new ProcessBuilder(command);重定向 stderr（读取 FFmpeg 消息所需），没有它，sub-process 停止：
pb.redirectErrorStream(true);启动 FFmpeg sub-process，并创建
BufferedReader:Process process = pb.start(); BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));创建
OutputStream用于写入 FFmpeg 的标准输入管道 sub-process:OutputStream writer = process.getOutputStream();循环将原始视频帧写入 FFmpeg sub-process 的标准输入管道：
byte img[] = new byte[width*height*3]; for (int i = 0; i < n_frmaes; i++) { //Fill img with pixel data ... writer.write(img); }关闭stdin，读取并打印stderr内容，等待sub-process完成：
writer.close(); String line; while ((line = reader.readLine()) != null) { System.out.println(line); } process.waitFor();
代码示例：
以下代码示例将 10 个大小为 192x108 的原始视频帧写入 FFmpeg。
我们不是将流式传输到 RTMP，而是将结果写入 test.flv 文件（用于测试）。
该示例使用硬编码字符串和数字（为简单起见）。
注：
代码示例假设 FFmpeg 可执行文件在执行路径中。
package myproject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
public class FfmpegVideoWriter {
public static void main(String[] args) throws IOException, InterruptedException {
final String rtmp_url = "test.flv"; //Set output file (instead of output URL) for testing.
final String command[] = {"ffmpeg",
"-y", //Add "-re" for simulated readtime streaming.
"-f", "rawvideo",
"-vcodec", "rawvideo",
"-pix_fmt", "bgr24",
"-s", "192x108",
"-r", "10",
"-i", "pipe:",
"-c:v", "libx264",
"-pix_fmt", "yuv420p",
"-preset", "ultrafast",
"-f", "flv",
rtmp_url};
//
ProcessBuilder pb = new ProcessBuilder(command); //Create ProcessBuilder
pb.redirectErrorStream(true); //Redirect stderr
Process process = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
//Create OutputStream for writing to stdin pipe of FFmpeg sub-process.
OutputStream writer = process.getOutputStream();
byte img[] = new byte[192*108*3]; //Dummy image
//Write 10 video frames to stdin pipe of FFmpeg sub-process
for (int i = 0; i < 10; i++)
{
//Fill image with some arbitrary pixel values
for (int y = 0; y < 108; y++)
{
for (int x = 0; x < 192; x++)
{
//Arbitrary RGB values:
byte r = (byte)((x * y + i) % 255); //Red component
byte g = (byte)((x * y + i*10) % 255); //Green component
byte b = (byte)((x * y + i*20) % 255); //Blue component
img[(y*192 + x)*3] = b;
img[(y*192 + x)*3+1] = g;
img[(y*192 + x)*3+2] = r;
}
}
writer.write(img); //Write img to FFmpeg
}
writer.close(); //Close stdin pipe.
//Read and print stderr content
//Note: there may be cases when FFmpeg keeps printing messages, so it may not be the best solution to empty the buffer only at the end.
//We may consider adding an argument `-loglevel error` for reducing verbosity.
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
process.waitFor();
}
}
该代码已在我的 PC 上进行了测试（使用 Windows 10），但我不确定它是否适用于 Android...
上面的示例简单而通用，在您的情况下，您可以使用 rgba 像素格式并在 onFrame 方法中写入 FrameData。
示例视频帧（“任意像素值”）：
更新：
以下代码示例使用 JavaCV - 将 Mat 数据写入 FFmpeg：
package myproject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.Scalar;
import org.opencv.core.Point;
import org.opencv.imgproc.Imgproc;
public class FfmpegVideoWriter {
static { System.loadLibrary(Core.NATIVE_LIBRARY_NAME); }
//Build synthetic "raw BGR" image for testing
public static void buildRawFrame(Mat img, int i)
{
int p = img.cols() / 60; //Used as font size factor.
img.setTo(new Scalar(60, 60, 60)); //Fill image with dark gray color
String text = Integer.toString(i+1);
int font = Imgproc.FONT_HERSHEY_SIMPLEX;
Point pos = new Point(img.cols()/2-p*10*(text.length()), img.rows()/2+p*10);
Imgproc.putText(img, text, pos, font, p, new Scalar(255, 30, 30), p*2); //Blue number
}
public static void main(String[] args) throws IOException, InterruptedException {
final int cols = 192;
final int rows = 108;
final String rtmp_url = "test.flv"; //Set output file (instead of output URL) for testing.
final String command[] = {"ffmpeg",
"-y", //Add "-re" for simulated readtime streaming.
"-f", "rawvideo",
"-vcodec", "rawvideo",
"-pix_fmt", "bgr24",
"-s", (Integer.toString(cols) + "x" + Integer.toString(rows)),
"-r", "10",
"-i", "pipe:",
"-c:v", "libx264",
"-pix_fmt", "yuv420p",
"-preset", "ultrafast",
"-f", "flv",
rtmp_url};
//
ProcessBuilder pb = new ProcessBuilder(command); //Create ProcessBuilder
pb.redirectErrorStream(true); //Redirect stderr
Process process = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
//Create OutputStream for writing to stdin pipe of FFmpeg sub-process.
OutputStream writer = process.getOutputStream();
//Dummy image (BGR pixel format).
Mat img = new Mat(rows, cols, CvType.CV_8UC3, Scalar.all(0));
byte buffer[] = new byte[cols*rows*3]; //Byte array for storing img data
//Write 10 video frames to stdin pipe of FFmpeg sub-process
for (int i = 0; i < 10; i++)
{
buildRawFrame(img, i); //Build image with blue frame counter.
img.get(0, 0, buffer); //Copy img data to buffer (not sure if this is the best solution).
writer.write(buffer); //Write buffer (raw video frame as byte array) to FFmpeg
}
writer.close(); //Close stdin pipe.
//Read and print stderr content
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
process.waitFor();
}
}
示例输出帧：