我面临以下问题，我有一堆。bmp文件和一个。wav文件，我使用以下ffmpeg命令转换为mp4文件。
ffmpeg -i <input>.wav -i bmps/%5d.bmp -vcodec libx264 <output>.mp4
我的目标是使这个。mp4一个单一的。m4s段，可以使用媒体源扩展循环播放。[1]
ffmpeg -loglevel error -y
-i <output>.mp4
-vf scale=1280x720
-hls_segment_type fmp4
-vcodec libx264
-acodec aac
-b:a 128k
-pix_fmt yuv420p
-hls_flags independent_segments
-flags +cgop
-movflags frag_keyframe+empty_moov
-hls_time 1000
-r 25 -g 25 -bf 0
-ar 44100
-f hls
<output>.m3u8
下面是使用mp4info
创建。mp4文件File:
major brand: isom
minor version: 200
compatible brand: isom
compatible brand: iso2
compatible brand: avc1
compatible brand: mp41
fast start: no
Movie:
duration: 10065 (media timescale units)
duration: 10065 (ms)
time scale: 1000
fragments: no
Found 2 Tracks
Track 1:
flags: 3 ENABLED IN-MOVIE
id: 1
type: Video
duration: 9960 ms
language: und
media:
sample count: 249
timescale: 12800
duration: 127488 (media timescale units)
duration: 9960 (ms)
bitrate (computed): 1249.046 Kbps
display width: 1280.000000
display height: 720.000000
frame rate (computed): 25.000
Sample Description 0
Coding: avc1 (H.264)
Codec String: avc1.F4001F
AVC Profile: 244
AVC Profile Compat: 0
AVC Level: 31
AVC NALU Length Size: 4
AVC SPS: [67f4001f919b280a00b742000003000200000300641e30632c]
AVC PPS: [68ebe3c44844]
Width: 1280
Height: 720
Depth: 24
Track 2:
flags: 3 ENABLED IN-MOVIE
id: 2
type: Audio
duration: 10065 ms
language: und
media:
sample count: 218
timescale: 22050
duration: 222949 (media timescale units)
duration: 10111 (ms)
bitrate (computed): 79.182 Kbps
Sample Description 0
Coding: mp4a (MPEG-4 Audio)
Codec String: mp4a.40.2
Stream Type: Audio
Object Type: MPEG-4 Audio
Max Bitrate: 79181
Avg Bitrate: 79181
Buffer Size: 0
MPEG-4 Audio Object Type: 2 (AAC Low Complexity)
MPEG-4 Audio Decoder Config:
Sampling Frequency: 22050
Channels: 1
Extension:
Object Type: Spectral Band Replication
SBR Present: no
PS Present: no
Sampling Frequency: 0
Sample Rate: 22050
Sample Size: 16
Channels: 2
但重复一次后，视频卡住了。到目前为止我所尝试的:
- 将v:profile更改为high/main/baseline
- 将音频编解码器从aac切换到libfdk_aac
- 将音频比特率更改为128k/320k
- 使用320k的maxrate和minrate
谢谢[1]: https://jsfiddle.net/5cjnz9bf/2/
我们比较了音频流和视频流的长度，发现它们在长度上有一些差异(大约140ms)。我们添加了5帧(25fps ->200ms)，并将以下命令附加到ffmpeg，以便在audiostream的末尾添加无声音频填充:
-shortest -af apad
问题解决了。
确保视频流和音频流的长度相同。