Ffmpeg pts to timestamp 上面是理论介绍，下面来看如何通过代码来计算timestamp和换算成time. 2-win64. mkv -r 1000 -f image2 -frame_pts The presentation time (PTS) is the correct one. But what we really want is the PTS of our newly decoded raw frame, so we know when to display it. My guess is my way of setting pts and dts is wrong. This is due to ffmpeg's uint64_t v; // this is a 64bit integer, lowest 36 bits contain a timestamp with markers uint64_t pts = 0; pts |= (v >> 3) & (0x0007 << 30); // top 3 bits, shifted left by 3, other bits zeroed out pts |= (v >> 2) & (0x7fff << 15); // middle 15 bits pts |= (v >> 1) & (0x7fff << 0); // bottom 15 bits // pts now has correct timestamp without According to the documentation:. 820733) Let s be the desired start timestamp (here 81953. 0. pts*av_q2d(pFormatCtx->streams[stream_index]->time_base) * 1000. DTS： DTS（Decoding TimeStamp）解码时间戳，在视频packet进行解码成frame的 This structure describes decoded (raw) audio or video data. pts is supposed to give the time at which the frame has been decoded. starting at 2022-03-26T15:51:49. webm -show_packets -select_streams v -read_intervals %+#5 -v 0 -[PACKET] codec_type=video stream_index=0 pts=7 pts_time=0. copy /b *. The same documentation: If the format is set to localtime or gmtime, a third argument may be supplied: a strftime() format string. Can ffmpeg do this? Providing additional details, When I run the above command i get around 100 JPEGs, I guess there is a 1 to 1 (or many to 1) correspondence between these JPEGS and frames of the video. 4. Is that right ? But if I only seek to key frames using av_seek_frame, frame. 506 seconds. Decoding and displaying is working fine, except I'm not using timestamp info and get PTS/DTS（时间戳） 要想解决时间同步问题就必须要了解ffmpeg中的PTS和DTS到底是什么. at Mon Dec 19 04:45:42 CET 2011. /TB/1000 - Used for converting the PTS to milliseconds (assuming the numbers applies milliseconds). 有了上面 I/B/P帧的概念，我们再来理解 PTS/DTS 就非常容易了。PTS（Presentation TimeStamp）是渲染用的时间戳，也就是说，我们的视频帧是按照 PTS 的时间戳来展示的。DTS（Decoding TimeStamp）解码时间戳，是用于视频解码的。 那为什么有了 PTS 还要有 DTS呢？ FFMpeg version: 4. mp4" -filter:v "drawtext=text='%{pts\:hms}': x=(w-tw)/2: y=h-(2*lh): fontcolor=white: box=1: boxcolor=0x00000000@1: fontsize=(h/6)" "output. The expression is evaluated through the eval API and can contain the following constants: 'FRAME_RATE, FR' 文章浏览阅读8. 9k次。本文围绕FFmpeg展开，介绍了每帧图像的pts用于多路流同步。阐述了时间基转换及相关函数，列举常用时间戳类型，解释pts初始为负的原因。还讲述推流时rtcp、rtp时间戳的编码，以及ffmpeg rtsp、rtp解码流程和pts的计算方法，分多路和单路情况。 Use the setpts (set presentation timestamp) video filter (-vf). it is adding timestamp like this: I want to use different date format like this: Simple Date Format; Date and ffmpeg -fflags +genpts -i "sample. – I do understand that ffmpeg does not support precise seeking, so equality here means "something reasonably close". 4からはビットストリームフィルタでPTSを書き換えられるようになったので再エンコードコード不要で映像の再生速度を変更できる。 I decided to dig a little in the source to understand what's happening. ffprobe -v 0 -show_entries packet=pts,duration -of compact=p=0:nk=1 -read_intervals 999999 -select_streams v video. Follow edited Jan 27, 2020 at 19:28. 这次只需要显示每帧的pts，time_base，time因此不需要初始化output， 只要初始化input即可。 At whatever precision. It's relative presentation time depends on the start_time of the file, for which use -show_entries I would like to embed the computer's local time in milliseconds into a stream using FFMPEG. 7334,setpts=PTS-STARTPTS" -an output. 文章浏览阅读2. encoding: unused; decoding: Read by user. When copying from a DVB recording of a channel, to change the container type from MPEG TS to Matroska, the copy aborts as soon as it encounters a missing timestamp with the message: 在FFmpeg中，PTS（Presentation Timestamp）表示帧的显示时间，以时间基准（timebase）为单位。要将PTS转换为可读的时间格式，您可以使用以下方法： 1. I used a combination of methods: checking AVFrame. 000000 duration_ts=N/A duration=N/A bit_rate=N/A The generated file loogs like this : Video : start_pts=133508 start_time=1. Can ffmpeg set pts values of the output frames. When I first made this tutorial, all of my syncing code was pulled from ffplay. At least not for the hms format. I tried executing the following code, to check if it's a problem in my H264 stream: ffmpeg -f lavfi -i testsrc -t 3 -r 10 -pix_fmt yuv420p -c:v libx264 test. best_effort_timestamp, checking AVPacket. 2 DTS and PTS are different, despite not having B-frames (ffmpeg) Previous message: [FFmpeg-user] dshow: Multi channel Video Capture Cards for FFmpeg Next message: [FFmpeg-user] box=1" -c:a copy out. I use Live555 to parse H264 and feed the stream to my LibAV decoder. int64_t : pkt_pts : reordered pts from the last AVPacket that has been input into the decoder. Share. Definition at line 248 of file avutil. 50 seconds). Perhaps that value can help you decide when to stop reading. The alternative would then be to make sure PTS values (in outputFrame->pts) are created The pts function will just use the stored timestamp. 5. I came across this post from google trying to overlay time elapsed for my video. 0*PTS - half the speed; For example, to double the speed of a With this information, you can easily calculate the values for ffmpeg's -ss and -to parameters: Let b be the stream start timestamp (here 81824. Improve this answer. 506000 means an absolute presentation timestamp of 6. Made some changes and was able to get the timecode burn in for my video in Desired outcome. 000000 best_effort_timestamp=0 best_effort_timestamp_time=0. 264 and then use ffmpeg to encode and write timestamps to mp4? naushir Raspberry Pi Engineer & Forum Moderator Posts: 642 There is no way of burning the timestamp into the video. mp4 | tail -1 This will print values in the form of 118231200|3600 where the first value is the pts and the second the duration of the last packet of the video stream. I am trying to mux H264 encoded data and G711 PCM data into mov multimedia container. See here. What code have i used for this thus far: frame_time = frame->pts * av_q2d(video_dec_ctx->time_base) * 1000; where frame is AVFrame and video_dec_ctx is AVCodecContext. mp4 -vf "drawtext=fontfile=roboto. mkv -filter:v "setpts=0. pts Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will be presented to the user. Edit1: here is the output of ffprobe: ffprobe 480P_600K_71149981_vthumb. "--save-pts timestamps. But I'm still curious if it is possible to do [FFmpeg-devel] Converting pts to human-readable timestamp Michael Niedermayer michaelni at gmx. mp4 The code creates H264 synthetic video stream using ffmpeg, and then converts the stream ffmpeg -i "input. mp4 -vcodec copy -acodec copy -f mpegts file1. I am trying to extract the timestamps of mp4 video using ffmpeg. txt" saves a separate file with the timestamp of each frame that is in the encoded stream. That is simple enough as: ffmpeg -i input. I confirm the video duration will be correct unlike ffmpeg's concat. And there's no way to customize this timestamp format. -video_track_timescale 100000 - Set explicit Which ffmpeg command should I use to extract each frame number associated with its timestamp (time in ms from the starting of the video) ? ffprobe video. answered Oct I'm not able to display current timestamp like described in this post using text='%{pts\:hms}'. ts using, ffplay -i output1. 264 -vcodec copy test. mp4 and then the command from the post above works just fine. 1. 7. – My issue is that the start_pts is not 0 even if i use -copyts The original stremas looks like this : Audio & Video : start_pts=0 start_time=0. 264 videos use a 90 kHz clock for encoding timestamps. EDIT : Question. Fortunately, FFMpeg supplies us with a "best effort" timestamp, which you can get via, av_frame_get_best_effort_timestamp() First off, Use int64_t pts = av_frame_get_best_effort_timestamp(pFrame) to get the pts. setpts=PTS*10,drawtext=,setpts=PTS/10 where the factor 10 is the ratio of realtime between frames and their display interval in the timelapse video. 5 seconds from the keyframe's actual timestamp does the trick. Thus, we have to multiply them by 0. pkt_dts. mp4" The output will have the presentation time stamp (PTS) of each frame 2. A remuxing using PS: Check out this article/tutorial on A/V Sync with FFmpeg. According to the following post, we may use the following command for setting the file to Time Stamps in milliseconds: ffmpeg -vsync 0 -i video. m2ts" -c:v copy -an "output. It is used to synchronize the playback of different media streams and ensure that they are presented in the correct order. Improve this question. PTS copied from the AVPacket that was decoded to produce this frame. mp4 While the difference in the end timestamp is only 0. I have an input MPEG-2 TS file and I prefer to use some open source tool like ffmpeg or something similar. 264 ffmpeg -r 10 -i test. it shows 1. @NickvanTilborg I think that the question is asking for timestamps taken from within the video (PTS, Presentation Time Stamp) - so a frame taken from 1 minute 30 seconds into the video would have a filename like 00_01_30. . 483422 duration_ts=450449 duration=5. 04 seconds apart, they store a timestamp for each frame e. This is the command I used; ffmpeg -i & ffmpeg; timestamp; libx264; Share. Note The ASF header does NOT contain a correct start_time the ASF demuxer must NOT set this. ts -vf "select=gte(n\, [FRAME_INDEX])" -show_entries frame=pkt_pts_time -v quiet -of csv="p=0" -stats -y output. 在 FFmpeg 中，时间基(time_base)是时间戳(timestamp)的单位，时间戳值乘以时间基，可以得到实际的时刻值(以秒等为单位)。例如，如果一个视频帧的 dts 是 40，pts 是 160，其 time_base 是 1/1000 秒，那么可以计算出此视频帧的解码时刻是 40 毫秒(40/1000)，显示时刻是 Tutorial 05: Synching Video Code: tutorial05. A value of 20 indicates one or both of the following: Your encoding clock (i. 3. 8k次，点赞9次，收藏46次。ffmpeg中在不同是层（封装、编解码、数据）的采样率不同，为精确描述该其数值，使用结构AVRational来描述时基这一概念。一个时间戳在不同的时基下进行变化，获取精确延时(av_usleep函数)。_pts dts duration自动生成 See What is video timescale, timebase, or timestamp in ffmpeg? The setpts filter evaluates the expression and assigns the value as the timestamp for the current frame it is processing. E. If possible just skip the rescale. 000000Z and a second later in the video present 2022-03-26T15:51. Previous message: [FFmpeg-devel] Converting pts to human-readable timestamp Next message: [FFmpeg-devel] Image sequence file names Messages sorted by: According to ffmpeg docs a frame_pts option should also be available that would use timestamps in the saved frame filenames (which would not be ideal either, as I would still have to parse filenames to get them, but it's an alternative), but I don't seem to get it to work in ffmpeg-python. However, the file (. duration is just what it sounds - information of how long given frame would be displayed before switching to the next one. AVFrame is typically allocated once and then reused multiple times to hold different data (e. The format must be a 12-hour clock with seconds and meridiem, e. ; Elapsed 2 seconds since the video started: the video displays 00:02 / 02:30. vktks jtryk yfmsry oqt nqz pgq hijzkp ewvenyu usdqq jtfdf hddagnw halshn vzbbob kuqrk xvqwn