FFmpeg浅尝辄止（二）——YUV视频序列编码为视频 ~~ 新版修改版-调通

文章来源： FFmpeg浅尝辄止（二）——YUV视频序列编码为视频

针对新版FFmpeg进行修改后，VC2010调通

AVFormatContext* oc;
AVOutputFormat* fmt;
AVStream* video_st;
double video_pts;
uint8_t* video_outbuf;
uint8_t* picture_buf;
AVFrame* picture;
// AVFrame* pictureRGB;
int size;
int ret;
int video_outbuf_size;

FILE *fin = fopen("akiyo_qcif.yuv", "rb"); //视频源文件

const char* filename = "test.mpeg";
fmt = av_guess_format(NULL, filename, NULL);

int retValue = avformat_alloc_output_context2(&oc,fmt,NULL,filename);

oc->oformat = fmt;
_snprintf(oc->filename, sizeof(oc->filename), "%s", filename);

video_st = NULL;
if (fmt->video_codec != CODEC_ID_NONE)
{
AVCodecContext* c;
video_st = avformat_new_stream(oc, 0);
c = video_st->codec;
c->codec_id = fmt->video_codec;
c->codec_type = AVMEDIA_TYPE_VIDEO;
c->bit_rate = 400000;
c->width = 176;
c->height = 144;
c->time_base.num = 1;
c->time_base.den = 25;
c->gop_size = 12;
c->pix_fmt = PIX_FMT_YUV420P;
if (c->codec_id == CODEC_ID_MPEG2VIDEO)
{
c->max_b_frames = 2;
}
if (c->codec_id == CODEC_ID_MPEG1VIDEO)
{
c->mb_decision = 2;
}
if (!strcmp(oc->oformat->name, "mp4") ||
!strcmp(oc->oformat->name, "mov") ||
!strcmp(oc->oformat->name, "3gp"))
{
c->flags |= CODEC_FLAG_GLOBAL_HEADER;
}

/*if (av_set_parameters(oc, NULL)<0)
{
return;
} */
av_opt_set(c->priv_data,"preset","superfast",0);
av_opt_set(c->priv_data,"tune","zerolatency",0);
}

av_dump_format(oc, 0, filename, 1);

if (video_st)
{
AVCodecContext* c;
AVCodec* codec;
c = video_st->codec;
codec = avcodec_find_encoder(c->codec_id);
if (!codec)
{
return 0;
}
if (avcodec_open2(c, codec,NULL) < 0)
{
return 0;
}
if (!(oc->oformat->flags & AVFMT_RAWPICTURE))
{
video_outbuf_size = 200000;
video_outbuf = (uint8_t*)av_malloc(video_outbuf_size);
}
picture = avcodec_alloc_frame();
size = avpicture_get_size(c->pix_fmt, c->width, c->height);
picture_buf = (uint8_t*)av_malloc(size);
if (!picture_buf)
{
av_free(picture);
}
avpicture_fill((AVPicture*)picture, picture_buf, c->pix_fmt, c->width, c->height);
}

if (!(fmt->flags & AVFMT_NOFILE))
{
if (avio_open(&oc->pb, filename, AVIO_FLAG_WRITE) < 0)
{
return 0;
}
}
avformat_write_header(oc,NULL);

for (int i=0; i<300; i++)
{
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 (!video_st/* || video_pts >= 5.0*/)
{
break;
}
AVCodecContext* c;
c = video_st->codec;
size = c->width * c->height;

if (fread(picture_buf, 1, size*3/2, fin) < 0)
{
break;
}

picture->data[0] = picture_buf; // 亮度
picture->data[1] = picture_buf+ size; // 色度
picture->data[2] = picture_buf+ size*5/4; // 色度

// 如果是rgb序列，可能需要如下代码
// SwsContext* img_convert_ctx;
// img_convert_ctx = sws_getContext(c->width, c->height, PIX_FMT_RGB24, c->width, c->height, c->pix_fmt, SWS_BICUBIC, NULL, NULL, NULL);
// sws_scale(img_convert_ctx, pictureRGB->data, pictureRGB->linesize, 0, c->height, picture->data, picture->linesize);

if (oc->oformat->flags & AVFMT_RAWPICTURE)
{
AVPacket pkt;
av_init_packet(&pkt);
pkt.flags |= AV_PKT_FLAG_KEY;
pkt.stream_index = video_st->index;
pkt.data = (uint8_t*)picture;
pkt.size = sizeof(AVPicture);
ret = av_write_frame(oc, &pkt);
}
else
{
int out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
if (out_size > 0)
{
AVPacket pkt;
av_init_packet(&pkt);
pkt.pts = av_rescale_q(c->coded_frame->pts, c->time_base, video_st->time_base);
if (c->coded_frame->key_frame)
{
pkt.flags |= AV_PKT_FLAG_KEY;
}
pkt.stream_index = video_st->index;
pkt.data = video_outbuf;
pkt.size = out_size;
ret = av_write_frame(oc, &pkt);
}
}
}

if (video_st)
{
avcodec_close(video_st->codec);
// av_free(picture->data[0]);
av_free(picture);
av_free(video_outbuf);
// av_free(picture_buf);
}
av_write_trailer(oc);
for (int i=0; i<oc->nb_streams; i++)
{
av_freep(&oc->streams[i]->codec);
av_freep(&oc->streams[i]);
}
if (!(fmt->flags & AVFMT_NOFILE))
{
avio_close(oc->pb);
}
av_free(oc);