Why seek on ts file is so slow?

Question

I am dealing with a ts file, following is ffprobe output:

ffprobe version N-45589-gb6a0b8b-   http://johnvansickle.com/ffmpeg/    Copyright (c) 2007-2014 the FFmpeg developers
  built on Aug 28 2014 02:30:32 with gcc 4.8 (Debian 4.8.3-9)
  configuration: --enable-gpl --enable-version3 --disable-shared --disable-debug --enable-runtime-cpudetect --enable-libmp3lame --enable-libx264 --enable-libx265 --enable-libwebp --enable-libspeex --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-fontconfig --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-gray --enable-libopenjpeg --enable-libopus --disable-ffserver --enable-libass --enable-gnutls --cc=gcc-4.8
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  0.101 / 56.  0.101
  libavformat    56.  3.100 / 56.  3.100
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  0.103 /  5.  0.103
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
[hevc @ 0x298b4a0] No start code is found.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] No start code is found.
    Last message repeated 2 times
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] No start code is found.
    Last message repeated 7 times
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] No start code is found.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[hevc @ 0x298b4a0] PPS id out of range: 0
[hevc @ 0x298b4a0] Error parsing NAL unit #2.
[mpegts @ 0x2987560] decoding for stream 0 failed
[mpegts @ 0x2987560] Could not find codec parameters for stream 0 (Video: hevc ([36][0][0][0] / 0x0024)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, mpegts, from 'mp4box-jlsj-4k.ts':
  Duration: 00:02:15.00, start: 0.001111, bitrate: 31116 kb/s
  Program 1
    Stream #0:0[0x65]: Video: hevc ([36][0][0][0] / 0x0024), 25 tbr, 90k tbn, 90k tbc
    Stream #0:1[0x66]: Audio: eac3, 48000 Hz, 5.1(side), fltp, 448 kb/s

The problem I'm having is that seeking on this file is extremely slow, it took more than 1 minute to complete seek operation.

This ts file is 500MB in size, has 2,793,052 ts packets, 2,750,469 video packets, 137 video packets with random_acces_indicator. What's the possible reason for the slow seek? Why is ffmpeg reporting these errors? What do I need to do for the analysis?

how do you seek? In ffplay? Or using custom code in your application? — Ronald S. Bultje, Jun 30 '15 at 13:06
the command is just "ffprobe a.ts", I found in function mpegts_read_seek() of mpegts.c, calling read_seek2() is slow, but calling read_seek() is very fast. — skipper, Jul 01 '15 at 05:01

score 0 · Answer 1 · answered Jul 02 '15 at 04:18

0

I'm, by all mean, not a hevc expert but it seems the input file's container is damaged or have corrupted data in it.

Try re-package it by using: ffmpeg -i <<INPUT>> -c copy <<OUTPUT.ts>>. ffmpeg should report back if any issue arise or data is damaged on the file.

answered Jul 02 '15 at 04:18

EladG

794
9
21

The file is malformed. ffmpeg drops every video frame, only audi frames left in resulted file. – skipper Jul 02 '15 at 07:52

Why seek on ts file is so slow?

1 Answers1