FFmpeg: cur_dts is invalid
声明：转帖时请注明出处less
FFmpeg 版本3.0
调用ffmpeg执行转码时，发现会有以下打印信息：ide
cur_dts is invalid (this is harmless if it occurs once at the start per stream)this
ffmpeg.c对应代码以下：编码
/**
* Select the output stream to process.
*
* @return selected output stream, or NULL if none available
*/
static OutputStream *choose_output(void)
{
int i;
int64_t opts_min = INT64_MAX;
OutputStream *ost_min = NULL;
for (i = 0; i < nb_output_streams; i++) {
OutputStream *ost = output_streams[i];
int64_t opts = ost->st->cur_dts == AV_NOPTS_VALUE ? INT64_MIN :
av_rescale_q(ost->st->cur_dts, ost->st->time_base,
AV_TIME_BASE_Q);
if (ost->st->cur_dts == AV_NOPTS_VALUE)
av_log(NULL, AV_LOG_DEBUG, "cur_dts is invalid (this is harmless if it occurs once at the start per stream)\n");
if (!ost->finished && opts < opts_min) {
opts_min = opts;
ost_min = ost->unavailable ? NULL : ost;
}
}
return ost_min;
}
h264 encoder.c 初始化代码以下：命令行
/* Init frames. */
if( h->param.i_bframe_adaptive == X264_B_ADAPT_TRELLIS && !h->param.rc.b_stat_read )
h->frames.i_delay = X264_MAX(h->param.i_bframe,3)*4;
else
h->frames.i_delay = h->param.i_bframe;
if( h->param.rc.b_mb_tree || h->param.rc.i_vbv_buffer_size )
h->frames.i_delay = X264_MAX( h->frames.i_delay, h->param.rc.i_lookahead );
i_slicetype_length = h->frames.i_delay;
h->frames.i_delay += h->i_thread_frames - 1;
h->frames.i_delay += h->param.i_sync_lookahead;
h->frames.i_delay += h->param.b_vfr_input;
等待填满编码缓冲区代码以下：日志
/* ------------------- Setup new frame from picture -------------------- */
if( pic_in != NULL )
{
/* 1: Copy the picture to a frame and move it to a buffer */
x264_frame_t *fenc = x264_frame_pop_unused( h, 0 );
if( !fenc )
return -1;
if( x264_frame_copy_picture( h, fenc, pic_in ) < 0 )
return -1;
if( h->param.i_width != 16 * h->mb.i_mb_width ||
h->param.i_height != 16 * h->mb.i_mb_height )
x264_frame_expand_border_mod16( h, fenc );
fenc->i_frame = h->frames.i_input++;
if( fenc->i_frame == 0 )
h->frames.i_first_pts = fenc->i_pts;
if( h->frames.i_bframe_delay && fenc->i_frame == h->frames.i_bframe_delay )
h->frames.i_bframe_delay_time = fenc->i_pts - h->frames.i_first_pts;
if( h->param.b_vfr_input && fenc->i_pts <= h->frames.i_largest_pts )
x264_log( h, X264_LOG_WARNING, "non-strictly-monotonic PTS\n" );
h->frames.i_second_largest_pts = h->frames.i_largest_pts;
h->frames.i_largest_pts = fenc->i_pts;
if( (fenc->i_pic_struct < PIC_STRUCT_AUTO) || (fenc->i_pic_struct > PIC_STRUCT_TRIPLE) )
fenc->i_pic_struct = PIC_STRUCT_AUTO;
if( fenc->i_pic_struct == PIC_STRUCT_AUTO )
{
#if HAVE_INTERLACED
int b_interlaced = fenc->param ? fenc->param->b_interlaced : h->param.b_interlaced;
#else
int b_interlaced = 0;
#endif
if( b_interlaced )
{
int b_tff = fenc->param ? fenc->param->b_tff : h->param.b_tff;
fenc->i_pic_struct = b_tff ? PIC_STRUCT_TOP_BOTTOM : PIC_STRUCT_BOTTOM_TOP;
}
else
fenc->i_pic_struct = PIC_STRUCT_PROGRESSIVE;
}
if( h->param.rc.b_mb_tree && h->param.rc.b_stat_read )
{
if( x264_macroblock_tree_read( h, fenc, pic_in->prop.quant_offsets ) )
return -1;
}
else
x264_stack_align( x264_adaptive_quant_frame, h, fenc, pic_in->prop.quant_offsets );
if( pic_in->prop.quant_offsets_free )
pic_in->prop.quant_offsets_free( pic_in->prop.quant_offsets );
if( h->frames.b_have_lowres )
x264_frame_init_lowres( h, fenc );
/* 2: Place the frame into the queue for its slice type decision */
x264_lookahead_put_frame( h, fenc );
if( h->frames.i_input <= h->frames.i_delay + 1 - h->i_thread_frames )
{
/* Nothing yet to encode, waiting for filling of buffers */
pic_out->i_type = X264_TYPE_AUTO;
return 0;
}
}
else
{
/* signal kills for lookahead thread */
x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
h->lookahead->b_exit_thread = 1;
x264_pthread_cond_broadcast( &h->lookahead->ifbuf.cv_fill );
x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
}
以视频h264编码为例，该打印的数量与输出编码帧的时间有关：code
bframes ： consecutive B-frames before this P-frame视频
i_lookahead： Number of frames for frametype lookaheadci
i_thread_frames：/* Number of different frames being encoded by threads;
* 1 when sliced-threads is on. */input
i_sync_lookahead; /* threaded lookahead buffer */
b_vfr_input; /* VFR input. If 1, use timebase and timestamps for ratecontrol purposes.
* If 0, use fps only. */
ffmpeg命令行：
./ffmpeg -i test_2.flv -vcodec libx264 -r 10 -report -y -f flv test_2out.flv
x264 encoder.c中添加打印语句以下：
/* Init frames. */
if( h->param.i_bframe_adaptive == X264_B_ADAPT_TRELLIS && !h->param.rc.b_stat_read )
h->frames.i_delay = X264_MAX(h->param.i_bframe,3)*4;
else
h->frames.i_delay = h->param.i_bframe;
x264_log( h, X264_LOG_DEBUG,"X264 init1 delay:%d\n",h->frames.i_delay);
if( h->param.rc.b_mb_tree || h->param.rc.i_vbv_buffer_size )
h->frames.i_delay = X264_MAX( h->frames.i_delay, h->param.rc.i_lookahead );
x264_log( h, X264_LOG_DEBUG,"X264 init2 delay:%d\n",h->frames.i_delay);
i_slicetype_length = h->frames.i_delay;
h->frames.i_delay += h->i_thread_frames - 1;
x264_log( h, X264_LOG_DEBUG,"X264 init3 delay:%d\n",h->frames.i_delay);
h->frames.i_delay += h->param.i_sync_lookahead;
x264_log( h, X264_LOG_DEBUG,"X264 init4 delay:%d\n",h->frames.i_delay);
h->frames.i_delay += h->param.b_vfr_input;
x264_log( h, X264_LOG_DEBUG,"X264 init5 delay:%d\n",h->frames.i_delay);
打印日志：
[libx264 @ 0x335a580] X264 init1 delay:3 [libx264 @ 0x335a580] X264 init2 delay:40 [libx264 @ 0x335a580] X264 init3 delay:40 [libx264 @ 0x335a580] X264 init4 delay:40 [libx264 @ 0x335a580] X264 init5 delay:41
总结：
cur_dts is invalid (this is harmless if it occurs once at the start per stream) 打印信息与编码输出帧的延时有关，其中最主要与i_lookahead值有关。
当编码器有帧输出时，则不会出现该打印信息。
以下图所示，解码41帧后，第42帧开始进行编码。
[libx264 @ 0x335a580] x264 frame info........ [libx264 @ 0x335a580] x264 frame encoder info........ [libx264 @ 0x335a580] X264 input frame:41, delay frame:41, thread frame:1 [libx264 @ 0x335a580] x264 frame encoder finish........ choose_output, OutputStream stream cur_dts:0 ... cur_dts is invalid (this is harmless if it occurs once at the start per stream) choose_output, OutputStream stream cur_dts:3864 ... OutputStream filter is true ... process input, file index0, ... choose_output, OutputStream stream cur_dts:0 ... cur_dts is invalid (this is harmless if it occurs once at the start per stream) choose_output, OutputStream stream cur_dts:3890 ... OutputStream filter is true ... process input, file index0, ... choose_output, OutputStream stream cur_dts:0 ... cur_dts is invalid (this is harmless if it occurs once at the start per stream) choose_output, OutputStream stream cur_dts:3917 ... OutputStream filter is true ... process input, file index0, ... choose_output, OutputStream stream cur_dts:0 ... cur_dts is invalid (this is harmless if it occurs once at the start per stream) choose_output, OutputStream stream cur_dts:3943 ... OutputStream filter is true ... process input, file index0, ... [h264 @ 0x3355260] decoding video ....... [libx264 @ 0x335a580] x264 frame info........ [libx264 @ 0x335a580] x264 frame encoder info........ [libx264 @ 0x335a580] X264 input frame:42, delay frame:41, thread frame:1 [libx264 @ 0x335a580] frame= 0 QP=2.40 NAL=3 Slice:I Poc:0 I:1064 P:0 SKIP:0 size=1086 bytes [libx264 @ 0x335a580] x264 frame encoder finish........ [flv @ 0x3263460] flv enc type:0, dts:0 pts:200 choose_output, OutputStream stream cur_dts:-100 ..
注释：
libx264库在添加打印后，须要进行编译和安装，即make && make install
此外，ffmpeg也须要配置，编译和安装，才能使打印信息生效。
相关文章
- 1. License information is invalid
- 2. FFMPEG函数read_frame_internal()
- 3. 'CC_MD5' is invalid in C99”
- 4. FFmpeg函数avformat_find_stream_info()
- 5. EsgynDB Troubleshooting-Backup location is invalid
- 6. ERROR:JAVA_HOME is set to an invalid directory
- 7. DBI1131E The user ID ERROR: is invalid.
- 8. The POM for com.alibaba:druid:jar:1.1.10 is invalid
- 9. a sealed resource is missing or invalid
- 10. 警告 ： is invalid in C99
- 更多相关文章...
- • PHP password_verify() 函数 - PHP参考手册
- • Thymeleaf表单 - Thymeleaf 教程
- • Kotlin学习（一）基本语法
- • PHP Ajax 跨域问题最佳解决方案
相关标签/搜索
每日一句
-
每一个你不满意的现在，都有一个你没有努力的曾经。
欢迎关注本站公众号,获取更多信息
相关文章
- 1. License information is invalid
- 2. FFMPEG函数read_frame_internal()
- 3. 'CC_MD5' is invalid in C99”
- 4. FFmpeg函数avformat_find_stream_info()
- 5. EsgynDB Troubleshooting-Backup location is invalid
- 6. ERROR:JAVA_HOME is set to an invalid directory
- 7. DBI1131E The user ID ERROR: is invalid.
- 8. The POM for com.alibaba:druid:jar:1.1.10 is invalid
- 9. a sealed resource is missing or invalid
- 10. 警告 ： is invalid in C99