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• fftools/ffmpeg : fix -t inaccurate recording time

  15 mai 2021, par Shiwang.Xie

  fftools/ffmpeg : fix -t inaccurate recording time
  if input start time is not 0 -t is inaccurate doing stream copy,
  
  will record extra duration according to input start time.
  
  it should base on following cases :
  input video start time from 60s, duration is 300s,
  
  1. stream copy :
  
         ffmpeg -ss 40 -t 60 -i in.mp4 -c copy -y out.mp4
  
     open_input_file() will seek to 100 and set ts_offset to -100,
  
     process_input() will offset pkt->pts with ts_offset to make it 0,
  
     so when do_streamcopy() with -t, exits when ist->pts >= recording_time.
  2. stream copy with -copyts :
  
         ffmpeg -ss 40 -t 60 -copyts -i in.mp4 -c copy -y out.mp4
  
     open_input_file() will seek to 100 and set ts_offset to 0,
  
     process_input() will keep raw pkt->pts as ts_offset is 0,
  
     so when do_streamcopy() with -t, exits when
  
     ist->pts >= (recording_time>start_time>ctx->start_time).
  3. stream copy with -copyts -start_at_zero :
  
         ffmpeg -ss 40 -t 60 -copyts -start_at_zero -i in.mp4 -c copy -y out.mp4
  
     open_input_file() will seek to 120 and set ts_offset to -60 as start_to_zero option,
  
     process_input() will offset pkt->pts with input file start time,
  
     so when do_streamcopy() with -t, exits when ist->pts >= (recording_time>start_time).
  0      60     40      60                     360
  
  
  
  _______
  _____
  _______
  _______________________
  
  
        start   -ss     -t
  This fixes ticket #9141.
  Signed-off-by : Shiwang.Xie <shiwang.xie666@outlook.com>
  

  • [DH] fftools/ffmpeg.c

• How to download .m3u8 in once time

  11 octobre 2024, par Nabi K.A.Z.

  I have a .m3u8 file on remote host, with contain fixed numbers of chunk .ts file name, and not stream :

  



  #EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:11
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:9.736,
media_0.ts
#EXTINF:9.96,
media_1.ts
#EXTINF:10.0,
media_2.ts
#EXTINF:10.0,
media_3.ts
#EXTINF:10.0,
media_4.ts
#EXTINF:10.2,
media_5.ts
#EXTINF:10.0,


  



  When I use this command :

  



  # ffmpeg -i "http://example.com/chunklist.m3u8" file.mp4

frame=  582 fps=9.4 q=28.0 size=    1536kB time=00:00:23.21 bitrate= 542.1kbits/s dup=2 drop=4 speed=0.375x


  



  It works. But It get frame by frame video and very long time needed. (It takes time almost to playback the video.)

  



  But since the path of all the .ts files are known. (http://example.com/media_0.ts, http://example.com/media_1.ts, ...) There must be a way to get and merge them all at the same time.

  



  But How in ffmpeg directly ?!

  



  EDIT (try a solution) :

  



  For one solution, I know how can concatenation files with ffmpeg.

  



  ffmpeg -i "concat:0.ts|1.ts|2.ts|3.ts|4.ts|5.ts" -c copy output.mp4


  



  This ffmpeg command was great, and works in less 1 sec time !

  



  So try to download all .ts files with CURL with this command :

  



  curl \
http://example.com/media_0.ts -o 0.ts \
http://example.com/media_1.ts -o 1.ts \
http://example.com/media_2.ts -o 2.ts \
http://example.com/media_3.ts -o 3.ts \
http://example.com/media_4.ts -o 4.ts \
http://example.com/media_5.ts -o 5.ts


  



  But you can see result :

  



    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  687k  100  687k    0     0  75108      0  0:00:09  0:00:09 --:--:-- 74111
100  652k  100  652k    0     0  59404      0  0:00:11  0:00:11 --:--:-- 53400
100  673k  100  673k    0     0  48675      0  0:00:14  0:00:14 --:--:-- 55781
100  657k  100  657k    0     0  63573      0  0:00:10  0:00:10 --:--:-- 62494
100  671k  100  671k    0     0  39019      0  0:00:17  0:00:17 --:--:-- 40863
100  692k  100  692k    0     0  63480      0  0:00:11  0:00:11 --:--:-- 80049


  



  See, total download time was 72 sec, while the total duration of all parts is 59 sec ! that this time is very long !

  



  So sorry, download all parts and then concat that, was not good solution.

  



  EDIT 2

  



  I try for another .m3u8 file on the another server with difference URL :

  



  Download and concat together :

  



  ffmpeg -i "concat:\
http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_0.ts|\
http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_1.ts|\
http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_2.ts|\
http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_3.ts|\
http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_4.ts|\
http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_5.ts\
" -c copy -y output.ts


  



  Another command with input.txt URLs file.

  



  ffmpeg -f "concat" -i "input.txt" -c copy -y output.ts


  



  input.txt file :

  



  file 'http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_0.ts'
file 'http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_1.ts'
file 'http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_2.ts'
file 'http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_3.ts'
file 'http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_4.ts'
file 'http://184.72.239.149/vod/smil:BigBuckBunny.smil/media_w442897525_b560000_5.ts'


  



  Or this command some time if needed :

  



  ffmpeg -f "concat" -safe "0" -protocol_whitelist "file,http,https,tcp,tls" -i "input.txt" -c copy -y output.ts


  



  Finally, for that download speed was good, MAYBE my server target has limited bandwidth. :-(

  


• Wrong start time with encoded file ?

  13 décembre 2022, par Michael

  I get a encoded file and with ffprobe I saw it like :
But I have already set start_time in AVStream to zero, where this start time comes from ? I guess I have some uninitialized param somewhere..