我正在从一个窗口捕获视频流,我想将它重新发送到我的rtsp代理服务器。但是,似乎我无法正确地写入帧,但我可以在SDL窗口中显示所述帧。这是我的代码:
int StreamHandler::storeStreamData()
{
// Allocate video frame
pFrame = av_frame_alloc();
// Allocate an AVFrame structure
pFrameRGB = av_frame_alloc();
if (pFrameRGB == NULL)
throw myExceptions("Error : Can't alloc the frame.");
// Determine required buffer size and allocate buffer
numBytes = avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx->width,
pCodecCtx->height);
buffer = (uint8_t *)av_malloc(numBytes * sizeof(uint8_t));
// Assign appropriate parts of buffer to image planes in pFrameRGB
avpicture_fill((AVPicture *)pFrameRGB, buffer, AV_PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
//InitSdlDrawBack();
// initialize SWS context for software scaling
sws_ctx = sws_getContext(pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
SWS_LANCZOS,
NULL,
NULL,
NULL
);
SetPixelArray();
FfmpegEncoder enc("rtsp://127.0.0.1:1935/live/myStream");
i = 0;
while (av_read_frame(pFormatCtx, &packet) >= 0) {
if (packet.stream_index == videoindex) {
// Decode video frame
avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
if (frameFinished) {
i++;
//DrawFrame();
sws_scale(sws_ctx, (uint8_t const * const *)pFrame->data,
pFrame->linesize, 0, pCodecCtx->height,
pFrameRGB->data, pFrameRGB->linesize);
enc.encodeFrame(pFrameRGB, i);
}
}
// Free the packet that was allocated by av_read_frame
av_free_packet(&packet);
}
// Free the RGB image
av_free(buffer);
av_frame_free(&pFrameRGB);
// Free the YUV frame
av_frame_free(&pFrame);
// Close the codecs
avcodec_close(pCodecCtx);
avcodec_close(pCodecCtxOrig);
// Close the video file
avformat_close_input(&pFormatCtx);
return 0;
}
void StreamHandler::SetPixelArray()
{
yPlaneSz = pCodecCtx->width * pCodecCtx->height;
uvPlaneSz = pCodecCtx->width * pCodecCtx->height / 4;
yPlane = (Uint8*)malloc(yPlaneSz);
uPlane = (Uint8*)malloc(uvPlaneSz);
vPlane = (Uint8*)malloc(uvPlaneSz);
if (!yPlane || !uPlane || !vPlane)
throw myExceptions("Error : Can't create pixel array.");
uvPitch = pCodecCtx->width / 2;
}
这里我填写YUV图像并写入数据包。
void FfmpegEncoder::encodeFrame(AVFrame * frame, int frameCount)
{
AVPacket pkt = { 0 };
int got_pkt;
av_init_packet(&pkt);
frame->pts = frameCount;
FillYuvImage(frame, frameCount, this->pCodecCtx->width, this->pCodecCtx->height);
if (avcodec_encode_video2(this->pCodecCtx, &pkt, frame, &got_pkt) < 0)
throw myExceptions("Error: failed to encode the frame. FfmpegEncoder.cpp l:61\n");
//if the frame is well encoded
if (got_pkt) {
pkt.stream_index = this->st->index;
pkt.pts = av_rescale_q_rnd(pkt.pts, this->pCodecCtx->time_base, this->st->time_base, AVRounding(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
if (av_write_frame(this->outFormatCtx, &pkt) < 0)
throw myExceptions("Error: failed to write video frame. FfmpegEncoder.cpp l:68\n");
}
}
void FfmpegEncoder::FillYuvImage(AVFrame * pict, int frame_index, int width, int height)
{
int x, y, i;
i = frame_index;
for (y = 0; y < height; y++)
{
for (x = 0; x < width / 2; x++)
pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
}
for (y = 0; y < height; y++)
{
for (x = 0; x < width / 2; x++)
{
pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
pict->data[2][y * pict->linesize[2] + x] = 64 + y + i * 5; //segault here
}
}
}
&#34; FillYuvImage&#34;方法是从FFMPEG示例中复制的,但它对我不起作用。如果我不打电话,那么&#34; av_write_frame&#34;功能不起作用(也是段错)。
编辑:这是我的输出上下文和编解码器初始化。
FfmpegEncoder::FfmpegEncoder(char *url)
{
AVRational tmp_time_base;
AVDictionary* options = NULL;
this->pCodec = avcodec_find_encoder(AV_CODEC_ID_H264);
if (this->pCodec == NULL)
throw myExceptions("Error: Can't initialize the encoder. FfmpegEncoder.cpp l:9\n");
this->pCodecCtx = avcodec_alloc_context3(this->pCodec);
//Alloc output context
if (avformat_alloc_output_context2(&outFormatCtx, NULL, "rtsp", url) < 0)
throw myExceptions("Error: Can't alloc stream output. FfmpegEncoder.cpp l:17\n");
this->st = avformat_new_stream(this->outFormatCtx, this->pCodec);
if (this->st == NULL)
throw myExceptions("Error: Can't create stream . FfmpegEncoder.cpp l:22\n");
av_dict_set(&options, "vprofile", "main", 0);
av_dict_set(&options, "tune", "zerolatency", 0);
tmp_time_base.num = 1;
tmp_time_base.den = 60;
//TODO : parse these values
this->pCodecCtx->bit_rate = 3000000;
this->pCodecCtx->width = 1280;
this->pCodecCtx->height = 720;
//This set the fps. 60fps at this point.
this->pCodecCtx->time_base = tmp_time_base;
//Add a intra frame every 12 frames
this->pCodecCtx->gop_size = 12;
this->pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
//Open Codec, using the context + x264 options
if (avcodec_open2(this->pCodecCtx, this->pCodec, &options) < 0)
throw myExceptions("Error: Can't open the codec. FfmpegEncoder.cpp l:43\n");
if (avcodec_copy_context(this->st->codec, this->pCodecCtx) != 0) {
throw myExceptions("Error : Can't copy codec context. FfmpegEncoder.cpp : l.46");
}
av_dump_format(this->outFormatCtx, 0, url, 1);
if (avformat_write_header(this->outFormatCtx, NULL) != 0)
throw myExceptions("Error: failed to connect to RTSP server. FfmpegEncoder.cpp l:48\n");
}
答案 0 :(得分:0)
for (y = 0; y < height; y++)
{
for (x = 0; x < width / 2; x++)
{
pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
pict->data[2][y * pict->linesize[2] + x] = 64 + y + i * 5; //segault here
}
}
应该是
for (y = 0; y < height / 2; y++) // Divide height by 2, you need only every other line
{
for (x = 0; x < width / 2; x++)
{
pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
pict->data[2][y * pict->linesize[2] + x] = 64 + y + i * 5; //segault here
}
}
YUV 420意味着每个2x2方格都有一个U和V样本,但是对于每个1x2平方,你的代码都在做一个样本,显然超出范围。