[英]iPhone camera shooting video using the AVCaptureSession and using ffmpeg CMSampleBufferRef a change in h.264 format is the issue. please advice
我的目标是 h.264/AAC,mpeg2-ts 从 iphone 设备流式传输到服务器。
目前我的源码是FFmpeg+libx264编译成功。 我知道 gnu 许可证。 我想要演示程序。
我想知道
1.CMSampleBufferRef 到 AVPicture 数据是否成功?
avpicture_fill((AVPicture*)pFrame, rawPixelBase, PIX_FMT_RGB32, width, height);
pFrame linesize and data is not null but pst -9233123123 . outpic also .
Because of this I have to guess 'non-strictly-monotonic PTS' message
2.这个日志是重复的。
encoding frame (size= 0)
encoding frame = "" , 'avcodec_encode_video' return 0 is success but always 0 .
我不知道该怎么办...
2011-06-01 15:15:14.199 AVCam[1993:7303] pFrame = avcodec_alloc_frame();
2011-06-01 15:15:14.207 AVCam[1993:7303] avpicture_fill = 1228800
Video encoding
2011-0601 15:5:14.215 AVCam[1993:7303] codec = 5841844
[libx264 @ 0x1441e00] using cpu capabilities: ARMv6 NEON
[libx264 @ 0x1441e00] profile Constrained Baseline, level 2.0[libx264 @ 0x1441e00] non-strictly-monotonic PTS
encoding frame (size= 0)
encoding frame
[libx264 @ 0x1441e00] final ratefactor: 26.74
3.我不得不猜测“非严格单调 PTS”消息是所有问题的原因。 这是什么“非严格单调的 PTS”。
~~~~~~~~~这是源码~~~~~~~~~~~~~~~~~~~~~
(void) captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
{
if( !CMSampleBufferDataIsReady(sampleBuffer) )
{
NSLog( @"sample buffer is not ready. Skipping sample" );
return;
}
if( [isRecordingNow isEqualToString:@"YES"] )
{
lastSampleTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer);
if( videoWriter.status != AVAssetWriterStatusWriting )
{
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:lastSampleTime];
}
if( captureOutput == videooutput )
{
[self newVideoSample:sampleBuffer];
CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
// access the data
int width = CVPixelBufferGetWidth(pixelBuffer);
int height = CVPixelBufferGetHeight(pixelBuffer);
unsigned char *rawPixelBase = (unsigned char *)CVPixelBufferGetBaseAddress(pixelBuffer);
AVFrame *pFrame;
pFrame = avcodec_alloc_frame();
pFrame->quality = 0;
NSLog(@"pFrame = avcodec_alloc_frame(); ");
// int bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
// int bytesSize = height * bytesPerRow ;
// unsigned char *pixel = (unsigned char*)malloc(bytesSize);
// unsigned char *rowBase = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
// memcpy (pixel, rowBase, bytesSize);
int avpicture_fillNum = avpicture_fill((AVPicture*)pFrame, rawPixelBase, PIX_FMT_RGB32, width, height);//PIX_FMT_RGB32//PIX_FMT_RGB8
//NSLog(@"rawPixelBase = %i , rawPixelBase -s = %s",rawPixelBase, rawPixelBase);
NSLog(@"avpicture_fill = %i",avpicture_fillNum);
//NSLog(@"width = %i,height = %i",width, height);
// Do something with the raw pixels here
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
//avcodec_init();
//avdevice_register_all();
av_register_all();
AVCodec *codec;
AVCodecContext *c= NULL;
int out_size, size, outbuf_size;
//FILE *f;
uint8_t *outbuf;
printf("Video encoding\n");
/* find the mpeg video encoder */
codec =avcodec_find_encoder(CODEC_ID_H264);//avcodec_find_encoder_by_name("libx264"); //avcodec_find_encoder(CODEC_ID_H264);//CODEC_ID_H264);
NSLog(@"codec = %i",codec);
if (!codec) {
fprintf(stderr, "codec not found\n");
exit(1);
}
c= avcodec_alloc_context();
/* put sample parameters */
c->bit_rate = 400000;
c->bit_rate_tolerance = 10;
c->me_method = 2;
/* resolution must be a multiple of two */
c->width = 352;//width;//352;
c->height = 288;//height;//288;
/* frames per second */
c->time_base= (AVRational){1,25};
c->gop_size = 10;//25; /* emit one intra frame every ten frames */
//c->max_b_frames=1;
c->pix_fmt = PIX_FMT_YUV420P;
c ->me_range = 16;
c ->max_qdiff = 4;
c ->qmin = 10;
c ->qmax = 51;
c ->qcompress = 0.6f;
/* open it */
if (avcodec_open(c, codec) < 0) {
fprintf(stderr, "could not open codec\n");
exit(1);
}
/* alloc image and output buffer */
outbuf_size = 100000;
outbuf = malloc(outbuf_size);
size = c->width * c->height;
AVFrame* outpic = avcodec_alloc_frame();
int nbytes = avpicture_get_size(PIX_FMT_YUV420P, c->width, c->height);
//create buffer for the output image
uint8_t* outbuffer = (uint8_t*)av_malloc(nbytes);
#pragma mark -
fflush(stdout);
<pre>// int numBytes = avpicture_get_size(PIX_FMT_YUV420P, c->width, c->height);
// uint8_t *buffer = (uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
//
// //UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"10%d", i]];
// CGImageRef newCgImage = [self imageFromSampleBuffer:sampleBuffer];//[image CGImage];
//
// CGDataProviderRef dataProvider = CGImageGetDataProvider(newCgImage);
// CFDataRef bitmapData = CGDataProviderCopyData(dataProvider);
// buffer = (uint8_t *)CFDataGetBytePtr(bitmapData);
//
// avpicture_fill((AVPicture*)pFrame, buffer, PIX_FMT_RGB8, c->width, c->height);
avpicture_fill((AVPicture*)outpic, outbuffer, PIX_FMT_YUV420P, c->width, c->height);
struct SwsContext* fooContext = sws_getContext(c->width, c->height,
PIX_FMT_RGB8,
c->width, c->height,
PIX_FMT_YUV420P,
SWS_FAST_BILINEAR, NULL, NULL, NULL);
//perform the conversion
sws_scale(fooContext, pFrame->data, pFrame->linesize, 0, c->height, outpic->data, outpic->linesize);
// Here is where I try to convert to YUV
/* encode the image */
out_size = avcodec_encode_video(c, outbuf, outbuf_size, outpic);
printf("encoding frame (size=%5d)\n", out_size);
printf("encoding frame %s\n", outbuf);
//fwrite(outbuf, 1, out_size, f);
// free(buffer);
// buffer = NULL;
/* add sequence end code to have a real mpeg file */
// outbuf[0] = 0x00;
// outbuf[1] = 0x00;
// outbuf[2] = 0x01;
// outbuf[3] = 0xb7;
//fwrite(outbuf, 1, 4, f);
//fclose(f);
free(outbuf);
avcodec_close(c);
av_free(c);
av_free(pFrame);
printf("\n");
这是因为每次“captureOutput:”迭代都会启动 AVCodecContext。 AVCodecContext 随着每一帧的到达连续保存编码的信息和 state。 因此,每个 session 或者如果高度和宽度或其他任何变化,都应该只进行一次所有初始化。 它还可以节省您的处理时间。 您收到的消息是完全有效的。 他们只是通知您有关编解码器的打开以及在哪些地方进行了编解码器方面的讨论。
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