[FFmpeg-user] How to extract 1 frame as JPEG per minute

[Ulf Zibis]

Hi,

Am 26.12.18 um 12:46 schrieb Carl Eugen Hoyos:
> $ mplayer -dumpstream dvd://
> or
> $ mplayer -dumpstream dvdnav://
I had to use:

$ mplayer -dumpstream -dumpfile CYD_dump.vob dvd:////dev/sr1

I got a file of 4.214.351.872 Bytes and following messages:

MPlayer 1.3.0 (Debian), built with gcc-7 (C) 2000-2016 MPlayer Team
do_connect: could not connect to socket
connect: No such file or directory
Failed to open LIRC support. You will not be able to use your remote
control.

Playing dvd:////dev/sr1.
*** Zero check failed in src/ifo_read.c:564
    for vmgi_mat->zero_3 = 0x00000000010000000000000000000000000000
There are 1 titles on this DVD.
There are 1 angles in this DVD title.

*** libdvdread: CHECK_VALUE failed in src/ifo_read.c:1230 ***
*** for n % 4 == 0 ***


libdvdread: Attempting to retrieve all CSS keys
libdvdread: This can take a _long_ time, please be patient

libdvdread: Get key for /VIDEO_TS/VIDEO_TS.VOB at 0x00000290
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_01_1.VOB at 0x00000b00
libdvdread: Elapsed time 0
libdvdread: Found 1 VTS's
libdvdread: Elapsed time 0
audio stream: 0 format: ac3 (stereo) language: unknown aid: 128.
number of audio channels on disk: 1.
number of subtitles on disk: 0

*** libdvdread: CHECK_VALUE failed in src/nav_read.c:264 ***
*** for dsi->dsi_gi.zero1 == 0 ***


*** libdvdread: CHECK_VALUE failed in src/nav_read.c:264 ***
*** for dsi->dsi_gi.zero1 == 0 ***


*** libdvdread: CHECK_VALUE failed in src/nav_read.c:264 ***
*** for dsi->dsi_gi.zero1 == 0 ***


*** libdvdread: CHECK_VALUE failed in src/nav_read.c:264 ***
*** for dsi->dsi_gi.zero1 == 0 ***


*** libdvdread: CHECK_VALUE failed in src/nav_read.c:264 ***
*** for dsi->dsi_gi.zero1 == 0 ***


*** libdvdread: CHECK_VALUE failed in src/nav_read.c:264 ***
*** for dsi->dsi_gi.zero1 == 0 ***

{.....}


With dvd::rip and subsequent cat I also got a vob file with
4.214.351.872 Bytes.

I do not see any difference or advantage with mplayer -dumpstream. They
are both a kind of corrupted, With VLC they stutter sometimes and the
time index is totally wrong, e.g. the length of the video is displayed
with 1:03 min instead 80:00 min.

After remuxing the file with:
ffmpeg -i in.vob -c copy out.vob
the file has 4.186.640.384 Bytes and then time index is correct and the
stuttering is gone.

But I still see the mentioned error messages when filtering and
transcoding the result to mp4.

-Ulf