From dbe941c078e2de2c21b48afe254a89183fcdd9c7 Mon Sep 17 00:00:00 2001 From: wenchao1024 <87457873+wenchao1024@users.noreply.github.com> Date: Thu, 6 Jan 2022 14:53:36 +0800 Subject: [PATCH] =?UTF-8?q?Update=20(=E8=BD=AC)FFMpeg=E5=86=99MP4=E6=96=87?= =?UTF-8?q?=E4=BB=B6=E4=BE=8B=E5=AD=90=E5=88=86=E6=9E=90.c?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- (转)FFMpeg写MP4文件例子分析.c | 633 +++++++++++++++++++++----- 1 file changed, 514 insertions(+), 119 deletions(-) diff --git a/(转)FFMpeg写MP4文件例子分析.c b/(转)FFMpeg写MP4文件例子分析.c index 653a7bb..164d2db 100644 --- a/(转)FFMpeg写MP4文件例子分析.c +++ b/(转)FFMpeg写MP4文件例子分析.c @@ -1,151 +1,546 @@ /** -使用FFMpeg可以很方便的对音视频进行编码，并且写文件。 +这段时间看了FFMpeg提供的例子muxing.c，我略微修改了下源代码，使其生成一个MP4文件，音频使用AAC编码，视频使用H.264编码。代码很简单，我就不做说明了，代码如下。 -下面的代码是将5幅1280*720大小的图片进行编码，并且写到文件中。 - -代码有些乱，但希望能抛砖引玉，对学习这方面的朋友有帮助。 +以后我们继续写如何将DirectShow中采集的音视频数据编码并生成MP4文件。 */ -CFile file[5]; -BYTE *szTxt[5]; +/* 5 seconds stream duration */ +#define STREAM_DURATION 5.0 +#define STREAM_FRAME_RATE 25 /* 25 images/s */ +#define STREAM_NB_FRAMES ((int)(STREAM_DURATION * STREAM_FRAME_RATE)) +#define STREAM_PIX_FMT PIX_FMT_YUV420P /* default pix_fmt */ -int nWidth = 0; -int nHeight= 0; +static int sws_flags = SWS_BICUBIC; -int nDataLen=0; +/**************************************************************/ +/* audio output */ -int nLen; +static float t, tincr, tincr2; +static int16_t *samples; +static uint8_t *audio_outbuf; +static int audio_outbuf_size; +static int audio_input_frame_size; -CString csFileName; -for (int fileI = 1; fileI <= 5; fileI ++) +/* +* add an audio output stream +*/ +static AVStream *add_audio_stream(AVFormatContext *oc, enum CodecID codec_id) { - csFileName.Format("e:\\pics\\%d.bmp", fileI); - file[fileI - 1].Open(csFileName,CFile::modeRead | CFile::typeBinary); - nLen = file[fileI - 1].GetLength(); + AVCodecContext *c; + AVStream *st; + + st = avformat_new_stream(oc, NULL); + if (!st) { + fprintf(stderr, "Could not alloc stream\n"); + exit(1); + } + st->id = 1; + + c = st->codec; + c->codec_id = codec_id; + c->codec_type = AVMEDIA_TYPE_AUDIO; + + /* put sample parameters */ + c->sample_fmt = AV_SAMPLE_FMT_S16; + c->bit_rate = 64000; + c->sample_rate = 44100; + c->channels = 2; + + // some formats want stream headers to be separate + if (oc->oformat->flags & AVFMT_GLOBALHEADER) + c->flags |= CODEC_FLAG_GLOBAL_HEADER; + + return st; +} - szTxt[fileI -1] = new BYTE[nLen]; - file[fileI - 1].Read(szTxt[fileI - 1], nLen); - file[fileI - 1].Close(); +static void open_audio(AVFormatContext *oc, AVStream *st) +{ + AVCodecContext *c; + AVCodec *codec; + + c = st->codec; + + /* find the audio encoder */ + codec = avcodec_find_encoder(c->codec_id); + if (!codec) { + fprintf(stderr, "codec not found\n"); + exit(1); + } + + /* open it */ + if (avcodec_open(c, codec) < 0) { + fprintf(stderr, "could not open codec\n"); + exit(1); + } + + /* init signal generator */ + t = 0; + tincr = 2 * M_PI * 110.0 / c->sample_rate; + /* increment frequency by 110 Hz per second */ + tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; + + audio_outbuf_size = 10000; + audio_outbuf = (uint8_t *)av_malloc(audio_outbuf_size); + + /* ugly hack for PCM codecs (will be removed ASAP with new PCM + support to compute the input frame size in samples */ + if (c->frame_size <= 1) { + audio_input_frame_size = audio_outbuf_size / c->channels; + switch(st->codec->codec_id) { + case CODEC_ID_PCM_S16LE: + case CODEC_ID_PCM_S16BE: + case CODEC_ID_PCM_U16LE: + case CODEC_ID_PCM_U16BE: + audio_input_frame_size >>= 1; + break; + default: + break; + } + } else { + audio_input_frame_size = c->frame_size; + } + samples = (int16_t *)av_malloc(audio_input_frame_size * 2 * c->channels); +} - //BMP bmi;//BITMAPINFO bmi; - //int nHeadLen = sizeof(BMP); - BITMAPFILEHEADER bmpFHeader; - BITMAPINFOHEADER bmpIHeader; - memcpy(&bmpFHeader,szTxt[fileI -1],sizeof(BITMAPFILEHEADER)); +/* prepare a 16 bit dummy audio frame of 'frame_size' samples and +'nb_channels' channels */ +static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels) +{ + int j, i, v; + int16_t *q; + + q = samples; + for (j = 0; j < frame_size; j++) { + v = (int)(sin(t) * 10000); + for(i = 0; i < nb_channels; i++) + *q++ = v; + t += tincr; + tincr += tincr2; + } +} - int nHeadLen = bmpFHeader.bfOffBits - sizeof(BITMAPFILEHEADER); - memcpy(&bmpIHeader,szTxt[fileI - 1]+sizeof(BITMAPFILEHEADER),nHeadLen); +static void write_audio_frame(AVFormatContext *oc, AVStream *st) +{ + AVCodecContext *c; + AVPacket pkt; + av_init_packet(&pkt); -nWidth = bmpIHeader.biWidth;// 464;// bmi.bmpInfo.bmiHeader.biWidth;// ; - nHeight = bmpIHeader.biHeight;//362;// bmi.bmpInfo.bmiHeader.biHeight;// ; + c = st->codec; - szTxt[fileI - 1] += bmpFHeader.bfOffBits; - nDataLen = nLen-bmpFHeader.bfOffBits; -} + get_audio_frame(samples, audio_input_frame_size, c->channels); -av_register_all(); -avcodec_register_all(); -AVFrame *m_pRGBFrame = new AVFrame[1]; //RGB帧数据 -AVFrame *m_pYUVFrame = new AVFrame[1];; //YUV帧数据 -AVCodecContext *c= NULL; -AVCodecContext *in_c= NULL; -AVCodec *pCodecH264; //编码器 -uint8_t * yuv_buff;// - -//查找h264编码器 -pCodecH264 = avcodec_find_encoder(CODEC_ID_H264); -if(!pCodecH264) -{ - fprintf(stderr, "h264 codec not found\n"); - exit(1); + pkt.size = avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples); + + if (c->coded_frame && c->coded_frame->pts != AV_NOPTS_VALUE) + pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base); + pkt.flags |= AV_PKT_FLAG_KEY; + pkt.stream_index = st->index; + pkt.data = audio_outbuf; + + /* write the compressed frame in the media file */ + if (av_interleaved_write_frame(oc, &pkt) != 0) { + fprintf(stderr, "Error while writing audio frame\n"); + exit(1); + } } -c= avcodec_alloc_context3(pCodecH264); -c->bit_rate = 3000000;// put sample parameters -c->width =nWidth;// -c->height = nHeight;// - -// frames per second -AVRational rate; -rate.num = 1; -rate.den = 25; -c->time_base= rate;//(AVRational){1,25}; -c->gop_size = 10; // emit one intra frame every ten frames -c->max_b_frames=1; -c->thread_count = 1; -c->pix_fmt = PIX_FMT_YUV420P;//PIX_FMT_RGB24; - -//av_opt_set(c->priv_data, /*"preset"*/"libvpx-1080p.ffpreset", /*"slow"*/NULL, 0); -//打开编码器 -if(avcodec_open2(c,pCodecH264,NULL)<0) - TRACE("不能打开编码库"); - -int size = c->width * c->height; - -yuv_buff = (uint8_t *) malloc((size * 3) / 2); // size for YUV 420 - -//将rgb图像数据填充rgb帧 -uint8_t * rgb_buff = new uint8_t[nDataLen]; - -//图象编码 -int outbuf_size=100000; -uint8_t * outbuf= (uint8_t*)malloc(outbuf_size); -int u_size = 0; -FILE *f=NULL; -char * filename = "e:\\pics\\myData.h264"; -f = fopen(filename, "wb"); -if (!f) +static void close_audio(AVFormatContext *oc, AVStream *st) { - TRACE( "could not open %s\n", filename); - exit(1); + avcodec_close(st->codec); + + av_free(samples); + av_free(audio_outbuf); } -//初始化SwsContext -SwsContext * scxt = sws_getContext(c->width,c->height,PIX_FMT_BGR24,c->width,c->height,PIX_FMT_YUV420P,SWS_POINT,NULL,NULL,NULL); +/**************************************************************/ +/* video output */ -AVPacket avpkt; +static AVFrame *picture, *tmp_picture; +static uint8_t *video_outbuf; +static int frame_count, video_outbuf_size; -//AVFrame *pTFrame=new AVFrame -for (int i=0;i<250;++i) +/* add a video output stream */ +static AVStream *add_video_stream(AVFormatContext *oc, enum CodecID codec_id) { + AVCodecContext *c; + AVStream *st; + AVCodec *codec; + + st = avformat_new_stream(oc, NULL); + if (!st) { + fprintf(stderr, "Could not alloc stream\n"); + exit(1); + } + + c = st->codec; + + /* find the video encoder */ + codec = avcodec_find_encoder(codec_id); + if (!codec) { + fprintf(stderr, "codec not found\n"); + exit(1); + } + avcodec_get_context_defaults3(c, codec); + + c->codec_id = codec_id; + + /* put sample parameters */ + c->bit_rate = /*400000*/3000000; + /* resolution must be a multiple of two */ + c->width = /*352*/640; + c->height = /*288*/480; + /* time base: this is the fundamental unit of time (in seconds) in terms + of which frame timestamps are represented. for fixed-fps content, + timebase should be 1/framerate and timestamp increments should be + identically 1. */ + c->time_base.den = STREAM_FRAME_RATE; + c->time_base.num = 1; + c->gop_size = 12; /* emit one intra frame every twelve frames at most */ + c->pix_fmt = STREAM_PIX_FMT; + if (c->codec_id == CODEC_ID_MPEG2VIDEO) { + /* just for testing, we also add B frames */ + c->max_b_frames = 2; + } + if (c->codec_id == CODEC_ID_MPEG1VIDEO){ + /* Needed to avoid using macroblocks in which some coeffs overflow. + This does not happen with normal video, it just happens here as + the motion of the chroma plane does not match the luma plane. */ + c->mb_decision=2; + } + // some formats want stream headers to be separate + if (oc->oformat->flags & AVFMT_GLOBALHEADER) + c->flags |= CODEC_FLAG_GLOBAL_HEADER; + + + + return st; +} - //AVFrame *m_pYUVFrame = new AVFrame[1]; +static AVFrame *alloc_picture(enum PixelFormat pix_fmt, int width, int height) +{ + AVFrame *picture; + uint8_t *picture_buf; + int size; + + picture = avcodec_alloc_frame(); + if (!picture) + return NULL; + size = avpicture_get_size(pix_fmt, width, height); + picture_buf = (uint8_t *)av_malloc(size); + if (!picture_buf) { + av_free(picture); + return NULL; + } + avpicture_fill((AVPicture *)picture, picture_buf, + pix_fmt, width, height); + return picture; +} - int index = (i / 25) % 5; - memcpy(rgb_buff,szTxt[index],nDataLen); +static void open_video(AVFormatContext *oc, AVStream *st) +{ + AVCodec *codec; + AVCodecContext *c; + + c = st->codec; + + /* find the video encoder */ + codec = avcodec_find_encoder(c->codec_id); + if (!codec) { + fprintf(stderr, "codec not found\n"); + exit(1); + } + + /* open the codec */ + if (avcodec_open(c, codec) < 0) { + fprintf(stderr, "could not open codec\n"); + exit(1); + } + + video_outbuf = NULL; + if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) { + /* allocate output buffer */ + /* XXX: API change will be done */ + /* buffers passed into lav* can be allocated any way you prefer, + as long as they're aligned enough for the architecture, and + they're freed appropriately (such as using av_free for buffers + allocated with av_malloc) */ + video_outbuf_size = 200000; + video_outbuf = (uint8_t *)av_malloc(video_outbuf_size); + } + + /* allocate the encoded raw picture */ + picture = alloc_picture(c->pix_fmt, c->width, c->height); + if (!picture) { + fprintf(stderr, "Could not allocate picture\n"); + exit(1); + } + + /* if the output format is not YUV420P, then a temporary YUV420P + picture is needed too. It is then converted to the required + output format */ + tmp_picture = NULL; + if (c->pix_fmt != PIX_FMT_YUV420P) { + tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height); + if (!tmp_picture) { + fprintf(stderr, "Could not allocate temporary picture\n"); + exit(1); + } + } +} - avpicture_fill((AVPicture*)m_pRGBFrame, (uint8_t*)rgb_buff, PIX_FMT_RGB24, nWidth, nHeight); +/* prepare a dummy image */ +static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height) +{ + int x, y, i; + + i = frame_index; + + /* Y */ + for (y = 0; y < height; y++) { + for (x = 0; x < width; x++) { + pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3; + } + } + + /* Cb and Cr */ + for (y = 0; y < height/2; 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 + x + i * 5; + } + } +} - //将YUV buffer 填充YUV Frame - avpicture_fill((AVPicture*)m_pYUVFrame, (uint8_t*)yuv_buff, PIX_FMT_YUV420P, nWidth, nHeight); +static void write_video_frame(AVFormatContext *oc, AVStream *st) +{ + int out_size, ret; + AVCodecContext *c; + static struct SwsContext *img_convert_ctx; + + c = st->codec; + + if (frame_count >= STREAM_NB_FRAMES) { + /* no more frame to compress. The codec has a latency of a few + frames if using B frames, so we get the last frames by + passing the same picture again */ + } else { + if (c->pix_fmt != PIX_FMT_YUV420P) { + /* as we only generate a YUV420P picture, we must convert it + to the codec pixel format if needed */ + if (img_convert_ctx == NULL) { + img_convert_ctx = sws_getContext(c->width, c->height, + PIX_FMT_YUV420P, + c->width, c->height, + c->pix_fmt, + sws_flags, NULL, NULL, NULL); + if (img_convert_ctx == NULL) { + fprintf(stderr, "Cannot initialize the conversion context\n"); + exit(1); + } + } + fill_yuv_image(tmp_picture, frame_count, c->width, c->height); + sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize, + 0, c->height, picture->data, picture->linesize); + } else { + fill_yuv_image(picture, frame_count, c->width, c->height); + } + } + + + if (oc->oformat->flags & AVFMT_RAWPICTURE) { + /* raw video case. The API will change slightly in the near + future for that. */ + AVPacket pkt; + av_init_packet(&pkt); + + pkt.flags |= AV_PKT_FLAG_KEY; + pkt.stream_index = st->index; + pkt.data = (uint8_t *)picture; + pkt.size = sizeof(AVPicture); + + ret = av_interleaved_write_frame(oc, &pkt); + } else { + /* encode the image */ + out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture); + /* if zero size, it means the image was buffered */ + if (out_size > 0) { + AVPacket pkt; + av_init_packet(&pkt); + + if (c->coded_frame->pts != AV_NOPTS_VALUE) + pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base); + if(c->coded_frame->key_frame) + pkt.flags |= AV_PKT_FLAG_KEY; + pkt.stream_index = st->index; + pkt.data = video_outbuf; + pkt.size = out_size; + +// printf("pts %d \n", c->coded_frame->pts); + + /* write the compressed frame in the media file */ + ret = av_interleaved_write_frame(oc, &pkt); + } else { + ret = 0; + } + } + if (ret != 0) { + fprintf(stderr, "Error while writing video frame\n"); + exit(1); + } + frame_count++; +} - // 翻转RGB图像 - m_pRGBFrame->data[0] += m_pRGBFrame->linesize[0] * (nHeight - 1); - m_pRGBFrame->linesize[0] *= -1; - m_pRGBFrame->data[1] += m_pRGBFrame->linesize[1] * (nHeight / 2 - 1); - m_pRGBFrame->linesize[1] *= -1; - m_pRGBFrame->data[2] += m_pRGBFrame->linesize[2] * (nHeight / 2 - 1); - m_pRGBFrame->linesize[2] *= -1; +static void close_video(AVFormatContext *oc, AVStream *st) +{ + avcodec_close(st->codec); + av_free(picture->data[0]); + av_free(picture); + if (tmp_picture) { + av_free(tmp_picture->data[0]); + av_free(tmp_picture); + } + av_free(video_outbuf); +} +/**************************************************************/ +/* media file output */ - //将RGB转化为YUV - sws_scale(scxt,m_pRGBFrame->data,m_pRGBFrame->linesize,0,c->height,m_pYUVFrame->data,m_pYUVFrame->linesize); - int got_packet_ptr = 0; - av_init_packet(&avpkt); - avpkt.data = outbuf; - avpkt.size = outbuf_size; - u_size = avcodec_encode_video2(c, &avpkt, m_pYUVFrame, &got_packet_ptr); - if (u_size == 0) - { - fwrite(avpkt.data, 1, avpkt.size, f); - } +int main(int argc, char **argv) +{ + const char *filename; + AVOutputFormat *fmt; + AVFormatContext *oc; + AVStream *audio_st, *video_st; + double audio_pts, video_pts; + int i; + + /* initialize libavcodec, and register all codecs and formats */ + av_register_all(); + +#if 0 + if (argc != 2) { + printf("usage: %s output_file\n" + "API example program to output a media file with libavformat.\n" + "The output format is automatically guessed according to the file extension.\n" + "Raw images can also be output by using '%%d' in the filename\n" + "\n", argv[0]); + return 1; + } + + filename = argv[1]; +#endif + +//#define RTMP_STREAM +#ifdef RTMP_STREAM + filename = "rtmp://192.168.0.239/live/livestream"; +#else + filename = "1.mp4"; +#endif + + /* allocate the output media context */ + avformat_alloc_output_context2(&oc, NULL, NULL, filename); + if (!oc) + { + printf("Could not deduce output format from file extension: using MPEG.\n"); + avformat_alloc_output_context2(&oc, NULL, /*"mpeg"*/"flv", filename); + } + + if (!oc) + { + return 1; + } + + // 强制指定 264 编码 + oc->oformat->video_codec = CODEC_ID_H264; + oc->oformat->audio_codec = CODEC_ID_AAC; + + fmt = oc->oformat; + + /* add the audio and video streams using the default format codecs + and initialize the codecs */ + video_st = NULL; + audio_st = NULL; + if (fmt->video_codec != CODEC_ID_NONE) { + video_st = add_video_stream(oc, fmt->video_codec); + } + if (fmt->audio_codec != CODEC_ID_NONE) { + audio_st = add_audio_stream(oc, fmt->audio_codec); + } + + av_dump_format(oc, 0, filename, 1); + + /* now that all the parameters are set, we can open the audio and + video codecs and allocate the necessary encode buffers */ + if (video_st) + open_video(oc, video_st); + if (audio_st) + open_audio(oc, audio_st); + + /* open the output file, if needed */ + if (!(fmt->flags & AVFMT_NOFILE)) { + if (avio_open(&oc->pb, filename, AVIO_FLAG_WRITE) < 0) { + fprintf(stderr, "Could not open '%s'\n", filename); + return 1; + } + } + + /* write the stream header, if any */ + avformat_write_header(oc, NULL); + picture->pts = 0; + for(;;) + { + /* compute current audio and video time */ + if (audio_st) + audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den; + else + audio_pts = 0.0; + + if (video_st) + video_pts = (double)video_st->pts.val * video_st->time_base.num / video_st->time_base.den; + else + video_pts = 0.0; + + if ((!audio_st || audio_pts >= STREAM_DURATION) && + (!video_st || video_pts >= STREAM_DURATION)) + break; + + /* write interleaved audio and video frames */ + if (!video_st || (video_st && audio_st && audio_pts < video_pts)) { + write_audio_frame(oc, audio_st); + + } else { + write_video_frame(oc, video_st); + + picture->pts++; + } + } + + /* write the trailer, if any. the trailer must be written + * before you close the CodecContexts open when you wrote the + * header; otherwise write_trailer may try to use memory that + * was freed on av_codec_close() */ + av_write_trailer(oc); + + /* close each codec */ + if (video_st) + close_video(oc, video_st); + if (audio_st) + close_audio(oc, audio_st); + + /* free the streams */ + for(i = 0; i < oc->nb_streams; i++) { + av_freep(&oc->streams[i]->codec); + av_freep(&oc->streams[i]); + } + + if (!(fmt->flags & AVFMT_NOFILE)) { + /* close the output file */ + avio_close(oc->pb); + } + + /* free the stream */ + av_free(oc); + + return 0; } - -fclose(f); -delete []m_pRGBFrame; -delete []m_pYUVFrame; -delete []rgb_buff; -free(outbuf); -avcodec_close(c); -av_free(c);