我有一个ffmpeg脚本。
我请求-b:v:0 1000k，但在我的主播放列表中得到了输出BANDWIDTH=1100000——我期待BANDWIDTH=1000000
正如您所看到的，没有音频流。为什么带宽每次都比请求的比特率大10%？
脚本：
ffmpeg -i rgb.mp4 -hide_banner # dump video stream info
rm -rf hls
ffmpeg -i rgb.mp4
-v warning -preset ultrafast -g 60 -sc_threshold 0
-map 0:0 -map 0:0 -map 0:0 -map 0:0
-s:v:0 1440x1080 -c:v:0 libx264 -b:v:0 1000k
-s:v:1 1440x1080 -c:v:1 libx264 -b:v:1 2000k
-s:v:2 1920x1440 -c:v:2 libx264 -b:v:2 3000k
-s:v:3 1920x1440 -c:v:3 libx264 -b:v:3 4000k
-var_stream_map "v:0 v:1 v:2 v:3"
-master_pl_name master.m3u8 -f hls
-hls_time 6 -hls_list_size 0 -hls_playlist_type vod
-hls_segment_filename "hls/v%v/chunk%d.ts" "hls/v%v/index.m3u8"
cat hls/master.m3u8
输出：
$ sh ./ffmpeg-test-script.sh
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'rgb.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
creation_time : 2021-08-03T11:45:50.000000Z
encoder : Lavf59.4.102
Duration: 00:00:50.04, start: 0.000000, bitrate: 37415 kb/s
Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 1920x1440, 37412 kb/s, 30 fps, 30 tbr, 19200 tbn (default)
Metadata:
creation_time : 2021-08-03T11:45:50.000000Z
handler_name : Core Media Video
vendor_id : [0][0][0][0]
Side data:
displaymatrix: rotation of -180.00 degrees
At least one output file must be specified
[swscaler @ 000001fae15daf00] deprecated pixel format used, make sure you did set range correctly
[swscaler @ 000001faef115ec0] deprecated pixel format used, make sure you did set range correctly
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-STREAM-INF:BANDWIDTH=1100000,RESOLUTION=1440x1080,CODECS="avc1.42c028"
v0/index.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=2200000,RESOLUTION=1440x1080,CODECS="avc1.42c028"
v1/index.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=3300000,RESOLUTION=1920x1440,CODECS="avc1.42c032"
v2/index.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=4400000,RESOLUTION=1920x1440,CODECS="avc1.42c032"
v3/index.m3u8
首先为x264编码器指定视频比特率，该比特率仅适用于来自编码器的比特。HLS播放列表中的BANDWITH参数包括容器(MPEG-2传输流(开销。