ср, 17 янв. 2024 г., 02:07 Terje J. Hanssen <[email protected]>:
> > > Den 16.01.2024 23:32, skrev Andrew Randrianasulu: > > > > ср, 17 янв. 2024 г., 01:14 Andrew Randrianasulu <[email protected]>: > >> >> >> ср, 17 янв. 2024 г., 01:04 Andrew Randrianasulu <[email protected] >> >: >> >>> >>> >>> ср, 17 янв. 2024 г., 00:42 Terje J. Hanssen <[email protected]>: >>> >>>> >>>> >>>> Den 16.01.2024 21:35, skrev Andrew Randrianasulu: >>>> >>>> >>>> >>>> вт, 16 янв. 2024 г., 23:30 Terje J. Hanssen <[email protected]>: >>>> >>>>> >>>>> >>>>> 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 >>> >>> https://forum.blackmagicdesign.com/viewtopic.php?f=33&t=171688 >>> >>> but still! >>> >> >> >> https://ieba.wordpress.com/2008/01/21/hdv-grows-up-sonys-hvr-s270-and-hvr-z7/ >> >> ===== >> *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. >> ===== >> > > > and samples: > > https://forum.doom9.org/archive/index.php/t-125966-p-46.html > > ===== > > As you can see 4 channel audio is part of the HDV format. I am not sure if > there are actually 2 audiostreams or only 1. There is no way I can check > this because the camera itself only outputs the 4 ch and no 2 ch. But the > computer will only play a 2 ch. But when you compare the MediaInfo audio > information with the specs I expect that there are 2 audio stream just like > eac3to detects. It would be very very nice if HDV support can be integrated > into eac3to because many professional cameramen are looking for an solution. > > Currently eac3to extracts the m2v and 2ch audio stream fine. Only the 4 > channel stream isn't detected nor extracted. I uploaded 2 sample to my > server for analysis: > http://tools.twanwintjes.nl/uploads/temp/00_0001_2010-11-07_153401.M2T > (49 seconds / 152MB) - Right Click --> Save As > http://tools.twanwintjes.nl/uploads/temp/00_0002_2010-11-07_214302.M2T > (44 seconds / 137MB) - Right Click --> Save As > > > ==== > > yes, files still there :) > > Yeah, I saw some of the forum threads and had a look on the sample files. > For me they the ffprobe outputs were identical with my own hdv.m2t files. > I think as Mullen wrote, the limit for miniDV or HDV tapes was utilized > for 1080i HD2 with 25 Mbps. > Only the 720p HD2 format with 19 Mbps had PCM tracs free for later use. > Maybe other camcorders.. > ===== > .2.1.8 Adaptive Multichannel Prediction Adaptive multichannel prediction is used to reduce the inter-channel redundancy. When using multichannel prediction, the signals in the transmission channels T2..T4 are predicted from the signals in the MPEG-1 compatible part of the bit stream (Lo, Ro). Instead of the actual signals in a subband group, the prediction error is transmitted, together with predictor coefficients and delay compensation. ======= from https://courses.e-ce.uth.gr/CE401/tree_menu/tutorials/MPEG2/13818-3.pdf > Possibly file storage on other disc media could be utilized for larger > bandwidth. > But I cannot see it was mentioned for the targeted camcorder disc recorder > > https://www.bhphotovideo.com/c/product/461819-REG/Sony_HVRDR60_HVRDR60_Hard_Disk_Recording.html > > >> >> >>> >>> >>>> >>>> >>>> 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 >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>> >>>> >
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