Android - 在使用WebRTC发送到Wowza Streaming Engine之前旋转视频帧 _Streaming

一身转战三千里，一剑曾百万师。这篇文章主要讲述Android - 在使用WebRTC发送到Wowza Streaming Engine之前旋转视频帧相关的知识，希望能为你提供帮助。
我想使用WebRTC将视频从android摄像头流式传输到Wowza Streaming Engine（WSE）。当设备处于横向模式时，一切运行良好。然后我尝试通过将设备置于纵向模式来进行流式传输。
我在WSE播放器中注意到的第一件事是视频流已逆时针旋转90度。我发现WebRTC在发送到WSE之前不会旋转从onPreviewFrame API发出的每个视频帧，不幸的是WSE不支持至少到目前为止在他们身边旋转视频帧的任何机制。
所以我检查了WebRTC android原生源代码并修改它以在发送到WSE之前旋转每个视频帧。现在我可以在WSE播放器中以纵向模式看到视频流。
但它有一个问题，有时视频流看起来很奇怪。请参阅以下图片。
A normal image
A weird image
【Android - 在使用WebRTC发送到Wowza Streaming Engine之前旋转视频帧】我把相机放到固定位置。 WSE播放器第一次显示第一个，但有时第二个显示。
这里是我改变的WebRTC源代码中的文件。 ?/的WebRTC / src目录/ SDK /安卓/ src目录/ JNI / androidvideotracksource.cc

void AndroidVideoTrackSource::OnByteBufferFrameCaptured(const void* frame_data, int length, int width, int height, VideoRotation rotation, int64_t timestamp_ns) { RTC_DCHECK(camera_thread_checker_.CalledOnValidThread()); int64_t camera_time_us = timestamp_ns / rtc::kNumNanosecsPerMicrosec; int64_t translated_camera_time_us = timestamp_aligner_.TranslateTimestamp(camera_time_us, rtc::TimeMicros()); int adapted_width; int adapted_height; int crop_width; int crop_height; int crop_x; int crop_y; if (!AdaptFrame(width, height, camera_time_us, & adapted_width, & adapted_height, & crop_width, & crop_height, & crop_x, & crop_y)) { return; }const uint8_t* y_plane = static_cast< const uint8_t*> (frame_data); const uint8_t* uv_plane = y_plane + width * height; const int uv_width = (width + 1) / 2; RTC_CHECK_GE(length, width * height + 2 * uv_width * ((height + 1) / 2)); // Can only crop at even pixels. crop_x & = ~1; crop_y & = ~1; // Crop just by modifying pointers. y_plane += width * crop_y + crop_x; uv_plane += uv_width * crop_y + crop_x; rtc::scoped_refptr< I420Buffer> buffer = buffer_pool_.CreateBuffer(adapted_width, adapted_height); nv12toi420_scaler_.NV12ToI420Scale( y_plane, width, uv_plane, uv_width * 2, crop_width, crop_height, buffer-> MutableDataY(), buffer-> StrideY(), // Swap U and V, since we have NV21, not NV12. buffer-> MutableDataV(), buffer-> StrideV(), buffer-> MutableDataU(), buffer-> StrideU(), buffer-> width(), buffer-> height()); // TODO: Rotate I420 frame 90 degrees clockwise. rtc::scoped_refptr< I420Buffer> rotated_buffer = I420Buffer::Rotate(*buffer, kVideoRotation_90); OnFrame(VideoFrame(rotated_buffer, rotation, translated_camera_time_us)); }

我添加了这行代码，顺时针旋转I420框架90度。

// TODO: Rotate I420 frame 90 degrees clockwise. rtc::scoped_refptr< I420Buffer> rotated_buffer = I420Buffer::Rotate(*buffer, kVideoRotation_90);

我将不胜感激任何帮助！
答案最后，我找到了解决这个问题的解决方案。以下是我的步骤：
第1步：确保将流媒体活动锁定为纵向
第2步：在WebRTC android本机源代码中更改此方法?/ webrtc / src / sdk / android / src / jni / androidvideotracksource.cc
原始版本：

void AndroidVideoTrackSource::OnByteBufferFrameCaptured(const void* frame_data, int length, int width, int height, VideoRotation rotation, int64_t timestamp_ns) { RTC_DCHECK(camera_thread_checker_.CalledOnValidThread()); int64_t camera_time_us = timestamp_ns / rtc::kNumNanosecsPerMicrosec; int64_t translated_camera_time_us = timestamp_aligner_.TranslateTimestamp(camera_time_us, rtc::TimeMicros()); int adapted_width; int adapted_height; int crop_width; int crop_height; int crop_x; int crop_y; if (!AdaptFrame(width, height, camera_time_us, & adapted_width, & adapted_height, & crop_width, & crop_height, & crop_x, & crop_y)) { return; }const uint8_t* y_plane = static_cast< const uint8_t*> (frame_data); const uint8_t* uv_plane = y_plane + width * height; const int uv_width = (width + 1) / 2; RTC_CHECK_GE(length, width * height + 2 * uv_width * ((height + 1) / 2)); // Can only crop at even pixels. crop_x & = ~1; crop_y & = ~1; // Crop just by modifying pointers. y_plane += width * crop_y + crop_x; uv_plane += uv_width * crop_y + crop_x; rtc::scoped_refptr< I420Buffer> buffer = buffer_pool_.CreateBuffer(adapted_width, adapted_height); nv12toi420_scaler_.NV12ToI420Scale( y_plane, width, uv_plane, uv_width * 2, crop_width, crop_height, buffer-> MutableDataY(), buffer-> StrideY(), // Swap U and V, since we have NV21, not NV12. buffer-> MutableDataV(), buffer-> StrideV(), buffer-> MutableDataU(), buffer-> StrideU(), buffer-> width(), buffer-> height()); OnFrame(VideoFrame(rotated_buffer, rotation, translated_camera_time_us)); }

修改版本：

void AndroidVideoTrackSource::OnByteBufferFrameCaptured(const void* frame_data, int length, int width, int height, VideoRotation rotation, int64_t timestamp_ns) { RTC_DCHECK(camera_thread_checker_.CalledOnValidThread()); int64_t camera_time_us = timestamp_ns / rtc::kNumNanosecsPerMicrosec; int64_t translated_camera_time_us = timestamp_aligner_.TranslateTimestamp(camera_time_us, rtc::TimeMicros()); int adapted_width; int adapted_height; int crop_width; int crop_height; int crop_x; int crop_y; if (!AdaptFrame(width, height, camera_time_us, & adapted_width, & adapted_height, & crop_width, & crop_height, & crop_x, & crop_y)) { return; }const uint8_t* y_plane = static_cast< const uint8_t*> (frame_data); const uint8_t* uv_plane = y_plane + width * height; const int uv_width = (width + 1) / 2; RTC_CHECK_GE(length, width * height + 2 * uv_width * ((height + 1) / 2)); // Can only crop at even pixels. crop_x & = ~1; crop_y & = ~1; // Crop just by modifying pointers. y_plane += width * crop_y + crop_x; uv_plane += uv_width * crop_y + crop_x; rtc::scoped_refptr< I420Buffer> buffer = buffer_pool_.CreateBuffer(adapted_width, adapted_height); nv12toi420_scaler_.NV12ToI420Scale( y_plane, width, uv_plane, uv_width * 2, crop_width, crop_height, buffer-> MutableDataY(), buffer-> StrideY(), // Swap U and V, since we have NV21, not NV12. buffer-> MutableDataV(), buffer-> StrideV(), buffer-> MutableDataU(), buffer-> StrideU(), buffer-> width(), buffer-> height()); // TODO: Comment out this line of code to apply custom code. // OnFrame(VideoFrame(buffer, rotation, translated_camera_time_us)); // TODO: The custom code to rotate video frame before passing // to next layers of WebRTC.// Rotate I420 frame rotation degrees. // Value of the rotation is 90 or 270 based on camera orientation. rtc::scoped_refptr< I420Buffer> rotated_buffer = I420Buffer::Rotate(*buffer, rotation); // Make sure the I420 frame has valid side in portrait mode. rtc::scoped_refptr< I420Buffer> final_buffer = buffer_pool_.CreateBuffer(height, width); final_buffer-> ScaleFrom(*rotated_buffer); // After rotating the I420 frame, set value of the rotation to 0. // This mean we do not want to rotate the frame in next layers anymore. rotation = kVideoRotation_0; // Pass processed frame to the next layers. OnFrame(VideoFrame(final_buffer, rotation, translated_camera_time_us)); }

现在我的流在Streaming Wowza Engine Player上完美显示。