av_strerror
int av_strerror ( int errnum,
char * errbuf,
size_t errbuf_size
)
ffmpeg获取与设置mp4文件旋转方向方法
设置与获取都是对AVStream的dict操作.
设置
for (i = 0; i < ifmt_ctx_v->nb_streams; i++) { //Create output AVStream according to input AVStream if(ifmt_ctx_v->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){ AVStream *in_stream = ifmt_ctx_v->streams[i]; AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec); videoindex_v=i; if (!out_stream) { printf( "Failed allocating output stream\n"); ret = AVERROR_UNKNOWN; goto end; } videoindex_out=out_stream->index; //Copy the settings of AVCodecContext ret = av_dict_set(&out_stream->metadata,"rotate","90",0); //设置旋转角度 if(ret>=0) { printf("=========yes=====set rotate success!===\n"); } if (avcodec_copy_context(out_stream->codec, in_stream->codec) < 0) { printf( "Failed to copy context from input to output stream codec context\n"); goto end; } out_stream->codec->codec_tag = 0; if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER) out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER; break; } }
读取
for (i = 0; i < ifmt_ctx_v->nb_streams; i++) { //Create output AVStream according to input AVStream if(ifmt_ctx_v->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){ AVStream *in_stream = ifmt_ctx_v->streams[i]; AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec); videoindex_v=i; if (!out_stream) { printf( "Failed allocating output stream\n"); ret = AVERROR_UNKNOWN; goto end; } videoindex_out=out_stream->index; //Copy the settings of AVCodecContext ret = av_dict_set(&out_stream->metadata,"rotate","90",0); //设置旋转角度 if(ret>=0) { printf("=========yes=====set rotate success!===\n"); } if (avcodec_copy_context(out_stream->codec, in_stream->codec) < 0) { printf( "Failed to copy context from input to output stream codec context\n"); goto end; } out_stream->codec->codec_tag = 0; if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER) out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER; break; } } double g_rotate_theta = get_rotation(decoder->is_video);//is_video是video的AVStreamint rotate = 0;if (fabs(g_rotate_theta - 90) < 1.0){rotate = 90;}else if(fabs(g_rotate_theta - 180) < 1.0||fabs(g_rotate_theta + 180) < 1.0){rotate = 180;}else if(fabs(g_rotate_theta - 270) < 1.0||fabs(g_rotate_theta + 90) < 1.0){rotate = 270;}LOGI("get rotate is : %d" , rotate);metadata->rotate = rotate;