我正在嘗試學習ffmpeg,MP4Box和MPEG-DASH,但是我遇到了我正在使用的.mp4版本的問題。我使用的ffmpeg來解複用器使用此命令MP4:MPEG-DASH - Multiplexed Representations問題
ffmpeg -i test.mp4 -c:v copy -g 72 -an video.mp4 -c:a copy audio.mp4
一旦創建兩個文件,我用這個命令使用MP4Box分割文件短跑選手:
MP4Box -dash 4000 -frag 1000 -rap -segment-name segment_ output.mp4
哪確實創建了我認爲我需要的所有文件。然後我點了玩家對output_dash.mpd並沒有任何反應,除了在控制檯一噸的消息:
[8] EME detected on this user agent! (ProtectionModel_21Jan2015)
[11] Playback Initialized
[21] [dash.js 2.3.0] MediaPlayer has been initialized
[64] Parsing complete: (xml2json: 3.42ms, objectiron: 2.61ms, total: 0.00603s)
[65] Manifest has been refreshed at Wed Apr 12 2017 12:16:52 GMT-0600 (MDT)[1492021012.196]
[72] MediaSource attached to element. Waiting on open...
[77] MediaSource is open!
[77] Duration successfully set to: 148.34
[78] Added 0 inline events
[78] No video data.
[79] No audio data.
[79] No text data.
[79] No fragmentedText data.
[79] No embeddedText data.
[80] Multiplexed representations are intentionally not supported, as they are not compliant with the DASH-AVC/264 guidelines
[81] No streams to play.
這裏是MP4Box -info上的視頻我使用:
* Movie Info *
Timescale 1000 - Duration 00:02:28.336
Fragmented File no - 2 track(s)
File suitable for progressive download (moov before mdat)
File Brand mp42 - version 512
Created: GMT Wed Feb 6 06:28:16 2036
File has root IOD (9 bytes)
Scene PL 0xff - Graphics PL 0xff - OD PL 0xff
Visual PL: Not part of MPEG-4 Visual profiles (0xfe)
Audio PL: Not part of MPEG-4 audio profiles (0xfe)
No streams included in root OD
iTunes Info:
Name: Rogue One - A Star Wars Story
Artist: Lucasfilm
Genre: Trailer
Created: 2016
Encoder Software: HandBrake 0.10.2 2015060900
Cover Art: JPEG File
Track # 1 Info - TrackID 1 - TimeScale 90000 - Duration 00:02:28.335
Media Info: Language "Undetermined" - Type "vide:avc1" - 3552 samples
Visual Track layout: x=0 y=0 width=1920 height=816
MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
AVC/H264 Video - Visual Size 1920 x 816
AVC Info: 1 SPS - 1 PPS - Profile High @ Level 4.1
NAL Unit length bits: 32
Pixel Aspect Ratio 1:1 - Indicated track size 1920 x 816
Self-synchronized
Track # 2 Info - TrackID 2 - TimeScale 44100 - Duration 00:02:28.305
Media Info: Language "English" - Type "soun:mp4a" - 6387 samples
MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x40
MPEG-4 Audio MPEG-4 Audio AAC LC - 2 Channel(s) - SampleRate 44100
Synchronized on stream 1
Alternate Group ID 1
我知道我需要分開視頻和音頻,我認爲這是我的問題所在。我正在使用的命令可能不是正確的。
是否有一個更好的命令demux我的mp4? 我使用的MP4Box命令是否最適合分割文件? 如果我使用不同的文件,他們總是需要解複用嗎?
有一點要提,如果我用下面的命令一切工作正常,但沒有因爲這意味着它的聲音只是視頻:
ffmpeg -i test.mp4 -c:v copy -g 72 -an output.mp4
MP4Box -dash 4000 -frag 1000 -rap -segment-name segment_ output.mp4
UPDATE
我注意到該視頻沒有音頻流,但音頻有視頻流,這就是爲什麼我得到了多路複用器錯誤。我是這麼認爲的,我跑這個命令,以保持不需要流出來的輸出可能是一個問題:
ffmpeg -i test.mp4 -c:v copy -g 72 -an video.mp4 -c:a copy -vn audio.mp4
然後我運行:
MP4Box -dash 4000 -frag 1000 -rap -segment-name segment_ video.mp4 audio.mp4
現在我不再得到復表示是故意不支持......的消息,但現在我得到:
[122] Video Element Error: MEDIA_ERR_SRC_NOT_SUPPORTED
[123] [object MediaError]
[125] Schedule controller stopping for audio
[126] Caught pending play exception - continuing (NotSupportedError: Failed to load because no supported source was found.)
我嘗試播放視頻和音頻獨立通過Chrome和他們都工作,只是沒有通過劃線的球員。呃,這是很痛苦的學習,但我覺得我正在取得進展。