Den 16.01.2024 21:35, skrev Andrew
Randrianasulu:
Den 16.01.2024 20:23, skrev Andrew Randrianasulu:
https://trac.ffmpeg.org/ticket/1258
see attached to this ticket modded
decoder ...
I wonder if Terje's audio really
4ch? if so,may be we can decode it to 4* wav
first, then encode them correctly to bluray lpcm /
dvd pcm / ac3 ...
I did leave out some "empty channels" to simplify and
clean up the post. Here are the full ffprobe output for
the HDV source (mediainfo was complete):
well, this ticket still open, so ffmpeg tools do
not know yet about this .. extension? It decodes in compat
stereo mode. I attached fixed decoder to this ticket, it will
be interesting if you just run ffmpeg acodec copy command and
then compile and run decoder on it .. it may decode to 4
files! But not sure how it all was arranged when it comes to
microphones ...? Does camera contain 4 of them? or you were
supposed to connect your own array?
Well, I think Steve Mullen's handbook for Sony FX7 (mine) and V1
clarify there is only two audo channels on my FX7::
- There is two types of HDV: HD1/720p (19 Mbps) and HD2/1080i
/25 Mbps) and Canon's 1080p24.
- HD1 is recorded to DV tape using only the DV video segment.
The PCM audio segment is open for future use.
- HD2 is recorded to DV tape using both the DV video segment and
the PCM audio segment. A small Subcode (ITI) segment holds data
such
- as timecode. Because no PCM audio segments are available, HD2
cannot carry record PCM audio.
- MPEG-1 Audio:
- Both HD1 and HD2 support two audio channels of audio signals
that are digitized with a 48kHz at 16-bit quantization and
compressed to
- 384kbps by MPEG-1 Audio Layer 2 encoding. ProHD adds
two-channel PCM audio thus creating a format that can carry four
independent
- channels of audio. (See Chapter 2 for an in-depth introduction
to MPEG-1 audio.)
yeah, seems to be rarely supported on HDV cameras, see
but still!
=====
4-Channel Audio
The HDV specification, like the DV specification, has allowed for
four-channel audio recording from the outset. Few cameras took advantage
of it, and when they did, it was an add-on that did not maintain full
balanced audio throughout. Though the smaller Sony HVR-Z7 records only
two channels of audio, the larger HVR-S270 has two XLR inputs in the
front of the camcorder and two XLR inputs on the back of the camcorder.
Each one has a separate audio level control and an automatic level
control switch on the side of the camcorder.
=====
ffprobe
-hide_banner hdv07_05.m2t
[mpeg2video
@ 0x55d58a968340] Invalid frame dimensions 0x0.
Last
message repeated 7 times
[mpegts @
0x55d58a93e580] Could not find codec parameters for
stream 2 (Unknown: none ([160][0][0][0] / 0x00A0)):
unknown codec
Consider
increasing the value for the 'analyzeduration' (0)
and 'probesize' (5000000) options
[mpegts @
0x55d58a93e580] Could not find codec parameters for
stream 3 (Unknown: none ([161][0][0][0] / 0x00A1)):
unknown codec
Consider
increasing the value for the 'analyzeduration' (0)
and 'probesize' (5000000) options
Input #0,
mpegts, from 'hdv07_05.m2t':
Duration: 00:06:58.27, start: 3276.528000, bitrate:
25626 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
Side
data:
cpb: bitrate max/min/avg: 25000000/0/0 buffer size:
7340032 vbv_delay: N/A
Stream
#0:1[0x814]: Audio: mp2 ([3][0][0][0] / 0x0003),
48000 Hz, stereo, fltp, 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)
Unsupported
codec with id 0 for input stream 2
Unsupported
codec with id 0 for input stream 3