sifutang/ffmpeg-demo

基于FFMpeg6.0的Android端播放Demo，包含基本的导入导出功能

ffmpeg-demo's Issues

从 frame->data 取的数据可能出现问题

void FFMpegPlayer::doRender(JNIEnv *env, AVFrame *avFrame) {
    if (avFrame->format == AV_PIX_FMT_YUV420P) {
        if (!avFrame->data[0] || !avFrame->data[1] || !avFrame->data[2]) {
            LOGE("doRender failed, no yuv buffer")
            return;
        }

        int ySize = avFrame->width * avFrame->height;
        auto y = env->NewByteArray(ySize);
        env->SetByteArrayRegion(y, 0, ySize, reinterpret_cast<const jbyte *>(avFrame->data[0]));
        auto u = env->NewByteArray(ySize / 4);
        env->SetByteArrayRegion(u, 0, ySize / 4, reinterpret_cast<const jbyte *>(avFrame->data[1]));
        auto v = env->NewByteArray(ySize / 4);
        env->SetByteArrayRegion(v, 0, ySize / 4, reinterpret_cast<const jbyte *>(avFrame->data[2]));

        if (mPlayerJni.isValid()) {
            env->CallVoidMethod(mPlayerJni.instance, mPlayerJni.onVideoFrameArrived,
                                avFrame->width, avFrame->height, FMT_VIDEO_YUV420, y, u, v);
        }

        env->DeleteLocalRef(y);
        env->DeleteLocalRef(u);
        env->DeleteLocalRef(v);
    } else if (avFrame->format == AV_PIX_FMT_NV12) {
        if (!avFrame->data[0] || !avFrame->data[1]) {
            LOGE("doRender failed, no nv21 buffer")
            return;
        }

        int ySize = avFrame->width * avFrame->height;
        auto y = env->NewByteArray(ySize);
        env->SetByteArrayRegion(y, 0, ySize, reinterpret_cast<const jbyte *>(avFrame->data[0]));
        auto uv = env->NewByteArray(ySize / 2);
        env->SetByteArrayRegion(uv, 0, ySize / 2, reinterpret_cast<const jbyte *>(avFrame->data[1]));

        if (mPlayerJni.isValid()) {
            env->CallVoidMethod(mPlayerJni.instance, mPlayerJni.onVideoFrameArrived,
                                avFrame->width, avFrame->height, FMT_VIDEO_NV12, y, uv, nullptr);
        }

        env->DeleteLocalRef(y);
        env->DeleteLocalRef(uv);
    } else if (avFrame->format == AV_PIX_FMT_RGBA) {
        if (!avFrame->data[0]) {
            LOGE("doRender failed, no rgba buffer")
            return;
        }

        int size = avFrame->width * avFrame->height * 4;
        auto rgba = env->NewByteArray(size);
        env->SetByteArrayRegion(rgba, 0, size, reinterpret_cast<const jbyte *>(avFrame->data[0]));

        if (mPlayerJni.isValid()) {
            env->CallVoidMethod(mPlayerJni.instance, mPlayerJni.onVideoFrameArrived,
                                avFrame->width, avFrame->height, FMT_VIDEO_RGBA, rgba, nullptr, nullptr);
        }

        env->DeleteLocalRef(rgba);
    } else if (avFrame->format == AV_PIX_FMT_MEDIACODEC) {
        av_mediacodec_release_buffer((AVMediaCodecBuffer *)avFrame->data[3], 1);
    } else if (avFrame->format == AV_SAMPLE_FMT_FLTP) {
        int dataSize = mAudioDecoder->mDataSize;
        bool flushRender = mAudioDecoder->mNeedFlushRender;
        if (dataSize > 0) {
            uint8_t *audioBuffer = mAudioDecoder->mAudioBuffer;
            if (mIsMute) {
                memset(audioBuffer, 0, dataSize);
            }
            auto jByteArray = env->NewByteArray(dataSize);
            env->SetByteArrayRegion(jByteArray, 0, dataSize, reinterpret_cast<const jbyte *>(audioBuffer));

            if (mPlayerJni.isValid()) {
                env->CallVoidMethod(mPlayerJni.instance, mPlayerJni.onAudioFrameArrived, jByteArray, dataSize, flushRender);
            }
            env->DeleteLocalRef(jByteArray);
        }
    }
}

你的这个方法里面是直接从 frame->data 中获取解码后的图片数据，而没有考虑 linesize，linesize 表示图片这行的数据大小，如果以 y 为例，通常是大于等于 image_width，当 linesize 等于 image_width 时，你的方法是没有问题的，但是当 linesize 大于 image_width 时你的方法就有问题，大于时需要一行一行地读取数据，需要忽略掉图片右边 linesize - imagewidth 的像素。

下面是我的参考代码：

void copyFrameData(uint8_t * dst, uint8_t * src, int image_width, int image_height, int line_stride, int pixel_stride) {
    if ((image_width * pixel_stride) >= line_stride) {
        memcpy(dst, src, image_width * image_height * pixel_stride);
    } else {
        uint8_t *dst_offset = dst;
        uint8_t *src_offset = src;
        int image_line_len = image_width * pixel_stride;
        for (int i = 0; i < image_height; i ++) {
            memcpy(dst_offset, src_offset, image_line_len);
            dst_offset += image_line_len;
            src_offset += line_stride;
        }
    }
}

// ...
// yuv420p
uint8_t *yBuffer = videoBuffer->yBuffer;
uint8_t *uBuffer = videoBuffer->uBuffer;
uint8_t *vBuffer = videoBuffer->vBuffer;
copyFrameData(yBuffer, frame->data[0], w, h, frame->linesize[0], 1);
copyFrameData(uBuffer, frame->data[1], w / 2, h / 2, frame->linesize[1], 1);
copyFrameData(vBuffer, frame->data[2], w / 2, h / 2, frame->linesize[2], 1);
//...

// ...
// yuv420sp
uint8_t *yBuffer = videoBuffer->yBuffer;
uint8_t *uvBuffer = videoBuffer->uvBuffer;
copyFrameData(yBuffer, frame->data[0], w, h, frame->linesize[0], 1);
copyFrameData(uvBuffer, frame->data[1], w / 2, h / 2, frame->linesize[1], 2);
// ...

// ...
// rgba
uint8_t *rgbaBuffer = videoBuffer->rgbaBuffer;
copyFrameData(rgbaBuffer, frame->data[0], w, h, frame->linesize[0], 4);

NV12 的 OpenGL 渲染器有问题

看上去是 U/V 值取反了，NV21 像你的这么取是对的.