FFMPEG Cutting Commercials使音频不同步

JaB*_*BbA 5 audio video ffmpeg h.264

加载了真正的ffmpeg的Ubuntu 14.04.1(avconv版本存在相同问题)。

我正在尝试使用HDPVR拍摄在MythTV中创建的文件,剪切广告并将视频放入MP4容器中,以便与MythRoku一起使用。

命令

ffmpeg -i $file -acodec copy -vcodec copy -f mp4 file.mp4

工作正常。更新数据库后,可以在MythRoku或Plex中观看文件。

但是,当我尝试剪切广告时,每当剪切超过0标记时,音频就会超过1秒(音频延迟)不同步。图腾视频播放器和VLC都可以很好地播放最终的视频,但是当它们同步音频时,我在开始时会看到一个“障碍”,所以我知道音频同步的信息在文件中的某个位置。播放文件时,Mythroku和Plex均不同步。MythTV Frontend播放器实际上确实可以正确播放它,并且在同步音频时,我可以听到“声音”。

经过数小时的阅读帖子和使用设置后,我将其归结为:

如果我说:

ffmpeg -i $file -acodec copy -vcodec copy -f mp4 -ss 0 -t <anything> out.mp4

该文件很好,可以在本地和MythRoku / Plex中播放

但是,如果我提前任何时间-甚至1秒-音频都不同步

ffmpeg -i $file -acodec copy -vcodec copy -f mp4 -ss 1 -t <anything> out.mp4

我尝试过先将视频(如mp4)和音频(如ac3)分开,分别分开,然后作为最后一步放回去,但是得到的结果是相同的。

信息在文件中-Totem,VLC和Frontend都可以解决。如何让ffmpeg找出同步并写入文件,使其正确无误?

原始文件:

mythtv@marvin:~$ mediainfo /var/lib/mythtv/recordings/2225_20140824001500.mpg
General
ID                                       : 0 (0x0)
Complete name                            :     /var/lib/mythtv/recordings/2225_20140824001500.mpg
Format                                   : MPEG-TS
File size                                : 4.03 GiB
Duration                                 : 1h 45mn
Overall bit rate mode                    : Variable
Overall bit rate                         : 5 491 Kbps

Video
ID                                       : 4113 (0x1011)
Menu ID                                  : 1 (0x1)
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.0
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 4 frames
Format settings, GOP                     : M=4, N=32
Codec ID                                 : 27
Duration                                 : 1h 45mn
Bit rate mode                            : Variable
Bit rate                                 : 4 831 Kbps
Maximum bit rate                         : 20.0 Mbps
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 59.940 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.087
Stream size                              : 3.55 GiB (88%)
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Audio
ID                                       : 4352 (0x1100)
Menu ID                                  : 1 (0x1)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Mode extension                           : CM (complete main)
Format settings, Endianness              : Big
Codec ID                                 : 129
Duration                                 : 1h 45mn
Bit rate mode                            : Constant
Bit rate                                 : 384 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits
Compression mode                         : Lossy
Delay relative to video                  : -6ms
Stream size                              : 289 MiB (7%)
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文件从0剪切:

mythtv@marvin:~$ mediainfo 2225_20140824001500_1.mp4
General
Complete name                            : 2225_20140824001500_1.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom
File size                                : 58.5 MiB
Duration                                 : 1mn 45s
Overall bit rate mode                    : Variable
Overall bit rate                         : 4 676 Kbps
Writing application                      : Lavf54.63.104

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.0
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 4 frames
Format settings, GOP                     : M=4, N=32
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 1mn 45s
Bit rate mode                            : Variable
Bit rate                                 : 4 281 Kbps
Maximum bit rate                         : 20.0 Mbps
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 59.940 fps
Minimum frame rate                       : 59.920 fps
Maximum frame rate                       : 59.960 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.077
Stream size                              : 53.6 MiB (92%)
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Audio
ID                                       : 2
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Mode extension                           : CM (complete main)
Format settings, Endianness              : Big
Codec ID                                 : ac-3
Duration                                 : 1mn 45s
Bit rate mode                            : Constant
Bit rate                                 : 384 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits
Compression mode                         : Lossy
Stream size                              : 4.81 MiB (8%)
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文件从1秒钟开始剪切,出现音频同步问题:

mythtv@marvin:~$ mediainfo 2225_20140824001500_2.mp4
General
Complete name                            : 2225_20140824001500_2.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom
File size                                : 68.0 MiB
Duration                                 : 2mn 0s
Overall bit rate mode                    : Variable
Overall bit rate                         : 4 750 Kbps
Writing application                      : Lavf54.63.104

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.0
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 4 frames
Format settings, GOP                     : M=4, N=32
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 1mn 58s
Bit rate mode                            : Variable
Bit rate                                 : 4 394 Kbps
Maximum bit rate                         : 20.0 Mbps
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 59.940 fps
Minimum frame rate                       : 59.920 fps
Maximum frame rate                       : 59.960 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.080
Stream size                              : 62.3 MiB (92%)
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Audio
ID                                       : 2
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Mode extension                           : CM (complete main)
Format settings, Endianness              : Big
Codec ID                                 : ac-3
Duration                                 : 2mn 0s
Bit rate mode                            : Constant
Bit rate                                 : 384 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits
Compression mode                         : Lossy
Stream size                              : 5.49 MiB (8%)
Run Code Online (Sandbox Code Playgroud)