我正在使用 ffmpeg 将 DSD 文件重新采样为 Flac 和 mp3。我没有遇到 mp3 重新采样的任何问题,但使用 flac 重新采样时,曲目末尾总会发出很大的咔嗒声,如下图所示:
我在命令行中使用一个基本命令:
ffmpeg -i input.dsf -ar 192000 -acodec flac output.flac
输出:
ffmpeg version 2.8.5 Copyright (c) 2000-2016 the FFmpeg developers
built with Apple LLVM version 7.0.2 (clang-700.1.81)
configuration: --prefix=/usr/local/Cellar/ffmpeg/2.8.5 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-vda
libavutil 54. 31.100 / 54. 31.100
libavcodec 56. 60.100 / 56. 60.100
libavformat 56. 40.101 / 56. 40.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 40.101 / 5. 40.101
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.101 / 1. 2.101
libpostproc 53. 3.100 / 53. 3.100
[mjpeg @ 0x7fe617809000] Changeing bps to 8
[dsf @ 0x7fe617000000] Estimating duration from bitrate, this may be inaccurate
Input #0, dsf, from 'input.dsf':
Metadata:
title : Bach Brandenburg no. 6 - Allegro
artist : Florilegium
album : Brandenburg Concertos
track : 3
Tool Version : 18.0.212
genre : Classical
composer : Bach
Catalog # : 35914
Format : DSD
ISRC : NLA460912792
Label : Channel Classics
Tool Name : Media Center
date : 2014
Duration: 00:06:00.31, bitrate: 5644 kb/s
Stream #0:0: Audio: dsd_lsbf_planar, 352800 Hz, stereo, fltp, 5644 kb/s
Stream #0:1: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 1429x1417 [SAR 300:300 DAR 1429:1417], 90k tbr, 90k tbn, 90k tbc
Metadata:
title : Picture
comment : Cover (front)
[flac @ 0x7fe617122000] encoding as 24 bits-per-sample
Output #0, flac, to 'output.flac':
Metadata:
title : Bach Brandenburg no. 6 - Allegro
artist : Florilegium
album : Brandenburg Concertos
TRACKNUMBER : 3
Tool Version : 18.0.212
genre : Classical
composer : Bach
Catalog # : 35914
Format : DSD
ISRC : NLA460912792
Label : Channel Classics
Tool Name : Media Center
date : 2014
encoder : Lavf56.40.101
Stream #0:0: Audio: flac, 192000 Hz, stereo, s32 (24 bit), 128 kb/s
Metadata:
encoder : Lavc56.60.100 flac
Stream mapping:
Stream #0:0 -> #0:0 (dsd_lsbf_planar (native) -> flac (native))
Press [q] to stop, [?] for help
size= 306541kB time=00:05:58.10 bitrate=7012.3kbits/s
video:0kB audio:306532kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.002733%
答案1
尝试更改-ar 192000
为-ar 176400
。
dsf
我在玩iPhone时也遇到过这种情况ffmpeg
。当我将输出采样率(又称:重采样率)设置为 48000 时,音频末尾会出现咔嗒声,但当我将输出采样率更改为 44100 时,一切正常。我认为这是因为重采样的原因,因为dsd
的采样率是以 44100 为单位测量的,例如dsd64
64*44100。
只是一个想法,尚未证实!