[Cin] HDV on a Blu-ray Disc Without Re-encoding

[Terje J. Hanssen]

This topic is treated with reference to the current  Cinelerra-GG Manual 
(and in the Features5 document at least since early 2018):

  * 14.6 HDV on a Blu-ray Disc Without Re-encoding

    An MTS file is a video file saved in the high-definition (HD) MPEG
    Transport Stream video format, commonly called AVCHD. It contains HD
    video compatible with Blu-ray disc format and is based on the MPEG-2
    transport stream. MTS files are often used by Sony, Panasonic, Canon
    and other HD camcorders. Legal in-
    put for Video – MPEG1VIDEO, MPEG2VIDEO, H264; Audio – MP1, MP2, AC3,
    AC3PLUS, DTS, TRUHD.

    For creating a blu-ray disc, if you have HDV MPEG-2 media that is in
    blu-ray format, you can save the original quality of your work,
    rather than rendering it to another format. Follow the steps below
    directly instead of going through C INELERRA-GG. It has been tested
    on 10 different MTS files.

    du -sb /yourHDVfile.MTS     # Determine the size of your file in bytes.

    blocks=((size-in-bytes/2048 + 4096))     # Convert bytes into blocks
    + a little more.

    mkudffs /tmp/newfilename.udfs blocks     # Create a file with that #
    of blocks + some extra.

    mount -o loop /tmp/newfilename.udfs /mntX     # Use a mount point
    like mntX that is not in use.

    /<cinelerra_installed_path>/bin/bdwrite /mntX /tmp/yourHDVfile.MTS
         # Substitute cinelerra path.

    umount /mntX    # You must unmount the udfs filesystem

    growisofs -Z /dev/bd=/tmp/newfilename.udfs     # Replace /dev/bd
    with your bluray hardware device.

    OR dd if=/tmp/newfilename.udfs of=/dev/bd bs=2048000     # if using
    rewritable blu-ray; replace bd.

===================

When the 1080i/25 HDV-source is recorded via i.Link (Firewire) to disk, 
the file type and format is HDV.M2T

For this test I use the same, downloaded HDV file as previous mentioned 
(not my file or camcorded by me!)

     Stream #0:0[0x810]: Video: mpeg2video (Main) ([2][0][0][0] / 
0x0002), yuv420p(tv, bt709, top first), 1440x1080 [SAR 4:3 DAR 16:9], 
25000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
     Stream #0:1[0x814]: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, 
stereo, s16p, 384 kb/s


The MPEG2 Video stream is Blu-ray compatible format, while the MP2 Audio 
stream has to be converted to AC3.

Demux, convert the audio and remux to a M2TS stream using this ffmpeg 
command:

ffmpeg -i 20081103140154.m2t -vcodec copy -acodec ac3 20081103140154.m2ts

............. skip

Input #0, mpegts, from '20081103140154.m2t':
   Duration: 00:00:13.44, start: 1042.400000, bitrate: 26598 kb/s
   Program 100
     Stream #0:0[0x810]: Video: mpeg2video (Main) ([2][0][0][0] / 
0x0002), yuv420p(tv, bt709, top first), 1440x1080 [SAR 4:3 DAR 16:9], 
25000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
     Stream #0:1[0x814]: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, 
stereo, s16p, 384 kb/s
     Stream #0:2[0x815]: Unknown: none ([160][0][0][0] / 0x00A0)
     Stream #0:3[0x811]: Unknown: none ([161][0][0][0] / 0x00A1)
Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (mp2 (native) -> ac3 (native))
Press [q] to stop, [?] for help
Output #0, mpegts, to '20081103140154.m2ts':
   Metadata:
     encoder         : Lavf57.83.100
     Stream #0:0: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), 
yuv420p(tv, bt709, top first), 1440x1080 [SAR 4:3 DAR 16:9], q=2-31, 
25000 kb/s, 25 fps, 25 tbr, 90k tbn, 90k tbc
     Stream #0:1: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s
     Metadata:
       encoder         : Lavc57.107.100 ac3
frame=  336 fps=0.0 q=-1.0 Lsize=   45549kB time=00:00:13.43 
bitrate=27774.3kbits/s speed= 107x
video:41008kB audio:315kB subtitle:0kB other streams:0kB global 
headers:0kB muxing overhead: 10.225909%

Comment
The default AC3 bitrate 192 kb/s here is halph of the source MP2 bitrate 
384 kb/s. Any idea about the quality difference?

================

So further to trouble using the procedure steps from the Manual above:

Determine the size of the file in bytes.

    du -sb 20081103140154.m2ts
    46642368    20081103140154.m2ts


Try to calculate the blocks as

    blocks=((/466423682048 + 4096)) = 26870.59375 ??


    # mkudffs /tmp/bd_20201122_hdv_m2ts.udfs blocks 26870.59375
    mkudffs: invalid block-count


Obviously something went wrong here.

Could someone test and verify these steps and further, to see if a 
successful Blu-ray BDAV structure is created?

(Just now I have no Blu-ray burner in my working PC, so I have to wait 
with burning the image to a BD-R/RE discs).

------------------

Terje J. H


One current and one previous related Blu-ray mail threads as references:
https://lists.cinelerra-gg.org/pipermail/cin/2020-November/002709.html
https://lists.cinelerra-cv.org/pipermail/cinelerra/2016q4/005609.html