音视频同步测试方法
目录
音视频同步测试方法
1.计算依据
延迟结果=图像出现时间-音频出现时间+客户端校验值(可正可负)
判断依据：一般延时结果在200ms内属于正常范围
2.获取视频信息
a.mediainfo
cd到视频文件的路径，然后在终端输入如下命令：
mediainfo a.mp4输出结果：
General
Complete name : a.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 13.1 MiB
Duration : 19 s 947 ms
Overall bit rate mode : Variable
Overall bit rate : 5 491 kb/s
Writing application : Lavf58.20.100
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 19 s 920 ms
Bit rate : 5 490 kb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 25.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.106
Stream size : 13.0 MiB (100%)
Writing library : x264 core 155 r2917 0a84d98
Encoding settings : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=21.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language : English
Codec configuration box : avcC
Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 19 s 947 ms
Bit rate mode : Variable
Bit rate : 2 277 b/s
Maximum bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 5.54 KiB (0%)
Language : English
Default : Yes
Alternate group : 1从输出结果可以看到延迟结果=(19.920-19.947)*1000=27ms，属于正常范围
b.ffprobe
cd到视频文件的路径，然后在终端输入如下命令：
ffprobe -v quiet -print_format json -show_format -show_streams -show_error -show_chapters a.mp4{
"streams": [
{
"index": 0,
"codec_name": "h264",
"codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
"profile": "High",
"codec_type": "video",
"codec_tag_string": "avc1",
"codec_tag": "0x31637661",
"width": 1920,
"height": 1080,
"coded_width": 1920,
"coded_height": 1080,
"closed_captions": 0,
"film_grain": 0,
"has_b_frames": 2,
"pix_fmt": "yuv420p",
"level": 40,
"chroma_location": "left",
"field_order": "progressive",
"refs": 1,
"is_avc": "true",
"nal_length_size": "4",
"id": "0x1",
"r_frame_rate": "25/1",
"avg_frame_rate": "25/1",
"time_base": "1/12800",
"start_pts": 0,
"start_time": "0.000000",
"duration_ts": 254976,
"duration": "19.920000",
"bit_rate": "5489806",
"bits_per_raw_sample": "8",
"nb_frames": "498",
"extradata_size": 43,
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0,
"captions": 0,
"descriptions": 0,
"metadata": 0,
"dependent": 0,
"still_image": 0
},
"tags": {
"language": "eng",
"handler_name": "\u001fMainconcept Video Media Handler",
"vendor_id": "[0][0][0][0]"
}
},
{
"index": 1,
"codec_name": "aac",
"codec_long_name": "AAC (Advanced Audio Coding)",
"profile": "LC",
"codec_type": "audio",
"codec_tag_string": "mp4a",
"codec_tag": "0x6134706d",
"sample_fmt": "fltp",
"sample_rate": "48000",
"channels": 2,
"channel_layout": "stereo",
"bits_per_sample": 0,
"id": "0x2",
"r_frame_rate": "0/0",
"avg_frame_rate": "0/0",
"time_base": "1/48000",
"start_pts": 0,
"start_time": "0.000000",
"duration_ts": 956400,
"duration": "19.925000",
"bit_rate": "2277",
"nb_frames": "935",
"extradata_size": 5,
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0,
"timed_thumbnails": 0,
"captions": 0,
"descriptions": 0,
"metadata": 0,
"dependent": 0,
"still_image": 0
},
"tags": {
"language": "eng",
"handler_name": "#Mainconcept MP4 Sound Media Handler",
"vendor_id": "[0][0][0][0]"
}
}
],
"chapters": [
],
"format": {
"filename": "a.mp4",
"nb_streams": 2,
"nb_programs": 0,
"format_name": "mov,mp4,m4a,3gp,3g2,mj2",
"format_long_name": "QuickTime / MOV",
"start_time": "0.000000",
"duration": "19.947000",
"size": "13691488",
"bit_rate": "5491146",
"probe_score": 100,
"tags": {
"major_brand": "isom",
"minor_version": "512",
"compatible_brands": "isomiso2avc1mp41",
"encoder": "Lavf58.20.100"
}
}
}从输出结果依然可以看到延迟结果=(19.920-19.947)*1000=27ms，属于正常范围