[FFmpeg-trac] #4617(undetermined:new): Incorrect timestamps if probing reads 1024 byes or less of a stream

FFmpeg trac at avcodec.org
Fri Jun 12 23:20:13 CEST 2015


#4617: Incorrect timestamps if probing reads 1024 byes or less of a stream
-------------------------------------+-------------------------------------
             Reporter:  ezran        |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 When an input stream has a low enough bitrate in the initial packets (such
 as audio with initial silence), the max_ts_probe setting (default of 50)
 can limit the amount of data read by avformat_find_stream_info such that
 less than 1024 bytes are read.  (For example, 50 packets of silent adts
 audio at 17 bytes per packet is only 850 bytes.)

 When this happens, the compute_pkt_fields and/or update_initial_timestamps
 don't happen until after the probe data is pulled from the packet buffer
 and processed.  The packets making up the first 1024 bytes don't get
 durations/timestamps computed during decoding, so then when the next 1024
 bytes are decoded (and those packets do get timestamps), the timestamps
 start back at zero.

 At that point, ffmpeg notices and adjusts the timestamps to try to
 compensate: "Non-monotonous DTS in output stream 0:1; previous: 121203,
 current: 0; changing to 121204. This may result in incorrect timestamps in
 the output file."  However, it assigns sequential PTS values to the
 packets while compensating, not taking the packet durations into account.
 This can lead to timestamps going backward in the output.

 This issue has existed since max_ts_probe was added (in 2.4, I think?)

 How to reproduce:
 {{{

 # Generate a silent audio file in adts format - first packet will be 30
 bytes, next 255 packets are 13 bytes.
 % ffmpeg -f lavfi -i 'aevalsrc=0|0' -c:a aac -t 10 -strict experimental
 silent.aac

 # Try to run that file through a basic conversion
 % ffmpeg -i silent.aac -y out.ts
 ... "Non-monotonous DTS in output stream 0:0; previous: 158882, current:
 324; changing to 158883. This may result in incorrect timestamps in the
 output file."

 # Run again, probing 78 packets so we read more than 1024 bytes during
 probe.  (30+13*77 = 1031)
 % ffmpeg -max_ts_probe 78 -i silent.aac -y out.ts
 ... No errors or warnings.

 # Run again, probing 77 packets so we read less than 1024 bytes during
 probe.  (30+13*76 = 1018)
 % ffmpeg -max_ts_probe 77 -i silent.aac -y out.ts
 ... "Non-monotonous DTS in output stream 0:0; previous: 158882, current:
 324; changing to 158883. This may result in incorrect timestamps in the
 output file."

 }}}

 Showing incorrect output timestamps:
 {{{

 # Basic conversion
 % ffmpeg -i silent.aac -y out.ts

 % ffprobe -show_frames out.ts | grep pkt_pts_time
 ... CUT ...
 pkt_pts_time=2.967278
 pkt_pts_time=2.993400
 pkt_pts_time=3.019533
 pkt_pts_time=3.045656
 pkt_pts_time=3.071778
 pkt_pts_time=3.097900
 pkt_pts_time=3.124022
 pkt_pts_time=3.150144
 pkt_pts_time=3.176267
 pkt_pts_time=3.202389
 pkt_pts_time=3.176289 <--- Backward
 pkt_pts_time=3.202411
 pkt_pts_time=3.176311 <--- Repeating
 pkt_pts_time=3.202433
 pkt_pts_time=3.176333
 ... CUT ...


 # Codec copy conversion
 % ffmpeg -i silent.aac -c:a copy -y out.ts
 ... CUT ...
 pkt_pts_time=5.254456
 pkt_pts_time=5.277678
 pkt_pts_time=5.300889
 pkt_pts_time=5.324111
 pkt_pts_time=3.559456 <--- Backward Jump
 pkt_pts_time=3.582678
 pkt_pts_time=3.605889
 pkt_pts_time=3.629111
 ... CUT ...

 }}}

 Full logs of basic conversion:
 {{{

 $ ffmpeg -v 9 -loglevel 99 -i silent.aac -y out.ts
 ffmpeg version N-72842-gfb92f3e Copyright (c) 2000-2015 the FFmpeg
 developers
   built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-3)
   configuration: --prefix=/usr --shlibdir=/usr/lib64 --libdir=/usr/lib64
 --incdir=/usr/include --bindir=/usr/bin --datadir=/usr/share/ffmpeg
 --mandir=/usr/share/man
   libavutil      54. 27.100 / 54. 27.100
   libavcodec     56. 41.100 / 56. 41.100
   libavformat    56. 36.100 / 56. 36.100
   libavdevice    56.  4.100 / 56.  4.100
   libavfilter     5. 16.101 /  5. 16.101
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  2.100 /  1.  2.100
 Splitting the commandline.
 Reading option '-v' ... matched as option 'v' (set logging level) with
 argument '9'.
 Reading option '-loglevel' ... matched as option 'loglevel' (set logging
 level) with argument '99'.
 Reading option '-i' ... matched as input file with argument 'silent.aac'.
 Reading option '-y' ... matched as option 'y' (overwrite output files)
 with argument '1'.
 Reading option 'out.ts' ... matched as output file.
 Finished splitting the commandline.
 Parsing a group of options: global .
 Applying option v (set logging level) with argument 9.
 Applying option y (overwrite output files) with argument 1.
 Successfully parsed a group of options.
 Parsing a group of options: input file silent.aac.
 Successfully parsed a group of options.
 Opening an input file: silent.aac.
 Probing aac score:51 size:2048
 Probing mpegts score:-1094995529 size:2048
 Probing msnwctcp score:-1 size:2048
 [aac @ 0x1d4f180] Format aac probed with size=2048 and score=51
 [aac @ 0x1d4f180] Before avformat_find_stream_info() pos: 0 bytes
 read:5650 seeks:0
 [aac @ 0x1d4f180] All info found
 [aac @ 0x1d4f180] Estimating duration from bitrate, this may be inaccurate
 [aac @ 0x1d4f180] 0: start_time: -9223372036854.775 duration: 284.887
 [aac @ 0x1d4f180] stream: start_time: -9223372036854.775 duration: 10.094
 bitrate=4 kb/s
 [aac @ 0x1d4f180] After avformat_find_stream_info() pos: 1024 bytes
 read:5650 seeks:0 frames:50
 Input #0, aac, from 'silent.aac':
   Duration: 00:00:10.09, bitrate: 4 kb/s
     Stream #0:0, 50, 1/28224000: Audio: aac (LC), 44100 Hz, stereo, fltp,
 4 kb/s
 Successfully opened the file.
 Parsing a group of options: output file out.ts.
 Successfully parsed a group of options.
 Opening an output file: out.ts.
 Successfully opened the file.
 detected 8 logical cores
 [graph 0 input from stream 0:0 @ 0x1d74840] Setting 'time_base' to value
 '1/44100'
 [graph 0 input from stream 0:0 @ 0x1d74840] Setting 'sample_rate' to value
 '44100'
 [graph 0 input from stream 0:0 @ 0x1d74840] Setting 'sample_fmt' to value
 'fltp'
 [graph 0 input from stream 0:0 @ 0x1d74840] Setting 'channel_layout' to
 value '0x3'
 [graph 0 input from stream 0:0 @ 0x1d74840] tb:1/44100 samplefmt:fltp
 samplerate:44100 chlayout:0x3
 [audio format for output stream 0:0 @ 0x1d4fae0] Setting 'sample_fmts' to
 value 's16'
 [audio format for output stream 0:0 @ 0x1d4fae0] Setting 'sample_rates' to
 value '44100|48000|32000|22050|24000|16000'
 [audio format for output stream 0:0 @ 0x1d4fae0] Setting 'channel_layouts'
 to value '0x4|0x3'
 [audio format for output stream 0:0 @ 0x1d4fae0] auto-inserting filter
 'auto-inserted resampler 0' between the filter 'Parsed_anull_0' and the
 filter 'audio format for output stream 0:0'
 [AVFilterGraph @ 0x1d6bae0] query_formats: 4 queried, 6 merged, 3 already
 done, 0 delayed
 [auto-inserted resampler 0 @ 0x1d5f960] ch:2 chl:stereo fmt:fltp r:44100Hz
 -> ch:2 chl:stereo fmt:s16 r:44100Hz
 [mpegts @ 0x1d71ee0] muxrate VBR, pcr every 3 pkts, sdt every 200, pat/pmt
 every 40 pkts
 Output #0, mpegts, to 'out.ts':
   Metadata:
     encoder         : Lavf56.36.100
     Stream #0:0, 0, 1/90000: Audio: mp2, 44100 Hz, stereo, s16, 384 kb/s
     Metadata:
       encoder         : Lavc56.41.100 mp2
 Stream mapping:
   Stream #0:0 -> #0:0 (aac (native) -> mp2 (native))
 Press [q] to stop, [?] for help
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158882, current: 324; changing to 158883. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158883, current: 2676; changing to 158884. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158884, current: 5027; changing to 158885. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158885, current: 7378; changing to 158886. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158886, current: 9729; changing to 158887. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158887, current: 12080; changing to 158888. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158888, current: 14431; changing to 158889. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158889, current: 16782; changing to 158890. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158890, current: 19133; changing to 158891. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158891, current: 21484; changing to 158892. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158892, current: 23835; changing to 158893. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158893, current: 26186; changing to 158894. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158894, current: 28537; changing to 158895. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158895, current: 30888; changing to 158896. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158896, current: 33239; changing to 158897. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158897, current: 35590; changing to 158898. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158898, current: 37941; changing to 158899. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158899, current: 40292; changing to 158900. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158900, current: 42643; changing to 158901. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158901, current: 44994; changing to 158902. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158902, current: 47345; changing to 158903. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158903, current: 49696; changing to 158904. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158904, current: 52047; changing to 158905. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158905, current: 54398; changing to 158906. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158906, current: 56749; changing to 158907. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158907, current: 59100; changing to 158908. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158908, current: 61451; changing to 158909. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158909, current: 63802; changing to 158910. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158910, current: 66153; changing to 158911. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158911, current: 68504; changing to 158912. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158912, current: 70855; changing to 158913. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158913, current: 73206; changing to 158914. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158914, current: 75557; changing to 158915. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158915, current: 77908; changing to 158916. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158916, current: 80259; changing to 158917. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158917, current: 82610; changing to 158918. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158918, current: 84961; changing to 158919. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158919, current: 87312; changing to 158920. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158920, current: 89663; changing to 158921. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158921, current: 92014; changing to 158922. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158922, current: 94365; changing to 158923. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158923, current: 96716; changing to 158924. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158924, current: 99067; changing to 158925. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158925, current: 101418; changing to 158926. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158926, current: 103769; changing to 158927. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158927, current: 106120; changing to 158928. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158928, current: 108471; changing to 158929. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158929, current: 110822; changing to 158930. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158930, current: 113173; changing to 158931. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158931, current: 115524; changing to 158932. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158932, current: 117876; changing to 158933. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158933, current: 120227; changing to 158934. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158934, current: 122578; changing to 158935. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158935, current: 124929; changing to 158936. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158936, current: 127280; changing to 158937. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158937, current: 129631; changing to 158938. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158938, current: 131982; changing to 158939. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158939, current: 134333; changing to 158940. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158940, current: 136684; changing to 158941. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158941, current: 139035; changing to 158942. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158942, current: 141386; changing to 158943. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158943, current: 143737; changing to 158944. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158944, current: 146088; changing to 158945. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158945, current: 148439; changing to 158946. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158946, current: 150790; changing to 158947. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158947, current: 153141; changing to 158948. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158948, current: 155492; changing to 158949. This may result in incorrect
 timestamps in the output file.
 [mpegts @ 0x1d71ee0] Non-monotonous DTS in output stream 0:0; previous:
 158949, current: 157843; changing to 158950. This may result in incorrect
 timestamps in the output file.
 [output stream 0:0 @ 0x1d74560] EOF on sink link output stream
 0:0:default.
 No more output streams to write to, finishing.
 size=     521kB time=00:00:08.23 bitrate= 518.5kbits/s
 video:0kB audio:470kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 10.811484%
 Input file #0 (silent.aac):
   Input stream #0:0 (audio): 432 packets read (5650 bytes); 432 frames
 decoded (442368 samples);
   Total: 432 packets (5650 bytes) demuxed
 Output file #0 (out.ts):
   Output stream #0:0 (audio): 384 frames encoded (442368 samples); 384
 packets muxed (481488 bytes);
   Total: 384 packets (481488 bytes) muxed
 432 frames successfully decoded, 0 decoding errors
 [AVIOContext @ 0x1d44c20] Statistics: 0 seeks, 192 writeouts
 [AVIOContext @ 0x1d44b20] Statistics: 5650 bytes read, 0 seeks

 }}}

 Full log of setting max_ts_probe to 78:
 {{{

 $ ffmpeg -v 9 -loglevel 99 -max_ts_probe 78 -i silent.aac -y out.ts
 ffmpeg version N-72842-gfb92f3e Copyright (c) 2000-2015 the FFmpeg
 developers
   built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-3)
   configuration: --prefix=/usr --shlibdir=/usr/lib64 --libdir=/usr/lib64
 --incdir=/usr/include --bindir=/usr/bin --datadir=/usr/share/ffmpeg
 --mandir=/usr/share/man
   libavutil      54. 27.100 / 54. 27.100
   libavcodec     56. 41.100 / 56. 41.100
   libavformat    56. 36.100 / 56. 36.100
   libavdevice    56.  4.100 / 56.  4.100
   libavfilter     5. 16.101 /  5. 16.101
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  2.100 /  1.  2.100
 Splitting the commandline.
 Reading option '-v' ... matched as option 'v' (set logging level) with
 argument '9'.
 Reading option '-loglevel' ... matched as option 'loglevel' (set logging
 level) with argument '99'.
 Reading option '-max_ts_probe' ... matched as AVOption 'max_ts_probe' with
 argument '78'.
 Reading option '-i' ... matched as input file with argument 'silent.aac'.
 Reading option '-y' ... matched as option 'y' (overwrite output files)
 with argument '1'.
 Reading option 'out.ts' ... matched as output file.
 Finished splitting the commandline.
 Parsing a group of options: global .
 Applying option v (set logging level) with argument 9.
 Applying option y (overwrite output files) with argument 1.
 Successfully parsed a group of options.
 Parsing a group of options: input file silent.aac.
 Successfully parsed a group of options.
 Opening an input file: silent.aac.
 Probing aac score:51 size:2048
 Probing mpegts score:-1094995529 size:2048
 Probing msnwctcp score:-1 size:2048
 [aac @ 0x312f300] Format aac probed with size=2048 and score=51
 [aac @ 0x312f300] Before avformat_find_stream_info() pos: 0 bytes
 read:5650 seeks:0
 [aac @ 0x312f300] All info found
 [aac @ 0x312f300] Estimating duration from bitrate, this may be inaccurate
 [aac @ 0x312f300] 0: start_time: -9223372036854.775 duration: 284.887
 [aac @ 0x312f300] stream: start_time: -9223372036854.775 duration: 10.094
 bitrate=4 kb/s
 [aac @ 0x312f300] After avformat_find_stream_info() pos: 2048 bytes
 read:5650 seeks:0 frames:78
 Input #0, aac, from 'silent.aac':
   Duration: 00:00:10.09, bitrate: 4 kb/s
     Stream #0:0, 78, 1/28224000: Audio: aac (LC), 44100 Hz, stereo, fltp,
 4 kb/s
 Successfully opened the file.
 Parsing a group of options: output file out.ts.
 Successfully parsed a group of options.
 Opening an output file: out.ts.
 Successfully opened the file.
 detected 8 logical cores
 [graph 0 input from stream 0:0 @ 0x311a400] Setting 'time_base' to value
 '1/44100'
 [graph 0 input from stream 0:0 @ 0x311a400] Setting 'sample_rate' to value
 '44100'
 [graph 0 input from stream 0:0 @ 0x311a400] Setting 'sample_fmt' to value
 'fltp'
 [graph 0 input from stream 0:0 @ 0x311a400] Setting 'channel_layout' to
 value '0x3'
 [graph 0 input from stream 0:0 @ 0x311a400] tb:1/44100 samplefmt:fltp
 samplerate:44100 chlayout:0x3
 [audio format for output stream 0:0 @ 0x311a840] Setting 'sample_fmts' to
 value 's16'
 [audio format for output stream 0:0 @ 0x311a840] Setting 'sample_rates' to
 value '44100|48000|32000|22050|24000|16000'
 [audio format for output stream 0:0 @ 0x311a840] Setting 'channel_layouts'
 to value '0x4|0x3'
 [audio format for output stream 0:0 @ 0x311a840] auto-inserting filter
 'auto-inserted resampler 0' between the filter 'Parsed_anull_0' and the
 filter 'audio format for output stream 0:0'
 [AVFilterGraph @ 0x311aa40] query_formats: 4 queried, 6 merged, 3 already
 done, 0 delayed
 [auto-inserted resampler 0 @ 0x3140b60] ch:2 chl:stereo fmt:fltp r:44100Hz
 -> ch:2 chl:stereo fmt:s16 r:44100Hz
 [mpegts @ 0x3152140] muxrate VBR, pcr every 3 pkts, sdt every 200, pat/pmt
 every 40 pkts
 Output #0, mpegts, to 'out.ts':
   Metadata:
     encoder         : Lavf56.36.100
     Stream #0:0, 0, 1/90000: Audio: mp2, 44100 Hz, stereo, s16, 384 kb/s
     Metadata:
       encoder         : Lavc56.41.100 mp2
 Stream mapping:
   Stream #0:0 -> #0:0 (aac (native) -> mp2 (native))
 Press [q] to stop, [?] for help
 [output stream 0:0 @ 0x311af40] EOF on sink link output stream
 0:0:default.
 No more output streams to write to, finishing.
 size=     521kB time=00:00:10.02 bitrate= 426.0kbits/s
 video:0kB audio:470kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 10.811484%
 Input file #0 (silent.aac):
   Input stream #0:0 (audio): 432 packets read (5650 bytes); 432 frames
 decoded (442368 samples);
   Total: 432 packets (5650 bytes) demuxed
 Output file #0 (out.ts):
   Output stream #0:0 (audio): 384 frames encoded (442368 samples); 384
 packets muxed (481488 bytes);
   Total: 384 packets (481488 bytes) muxed
 432 frames successfully decoded, 0 decoding errors
 [AVIOContext @ 0x31372e0] Statistics: 0 seeks, 192 writeouts
 [AVIOContext @ 0x312ebe0] Statistics: 5650 bytes read, 0 seeks

 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4617>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker


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