ffmpeg我在尝试使用/进行 H.264 编码的 Logitech C920 网络摄像头实现网络直播时遇到了一些麻烦ffserver。
这是我使用的配置文件ffserver：
# Port on which the server is listening. You must select a different
# port from your standard HTTP web server if it is running on the same
# computer.
Port 8090
# Address on which the server is bound. Only useful if you have
# several network interfaces.
BindAddress 0.0.0.0
# Number of simultaneous HTTP connections that can be handled. It has
# to be defined *before* the MaxClients parameter, since it defines the
# MaxClients maximum limit.
MaxHTTPConnections 2000
# Number of simultaneous requests that can be handled. Since FFServer
# is very fast, it is more likely that you will want to leave this high
# and use MaxBandwidth, below.
MaxClients 1000
# This the maximum amount of kbit/sec that you are prepared to
# consume when streaming to clients.
MaxBandwidth 1000
# Access log file (uses standard Apache log file format)
# '-' is the standard output.
CustomLog -
##################################################################
# Definition of the live feeds. Each live feed contains one video
# and/or audio sequence coming from an ffmpeg encoder or another
# ffserver. This sequence may be encoded simultaneously with several
# codecs at several resolutions.
<Feed feed.ffm>
# You must use 'ffmpeg' to send a live feed to ffserver. In this
# example, you can type:
#
File /tmp/feed.ffm
FileMaxSize 100M
# You could specify
# ReadOnlyFile /saved/specialvideo.ffm
# This marks the file as readonly and it will not be deleted or updated.
# Only allow connections from localhost to the feed.
ACL allow 127.0.0.1
</Feed>
##################################################################
# Now you can define each stream which will be generated from the
# original audio and video stream. Each format has a filename (here
# 'test1.mpg'). FFServer will send this stream when answering a
# request containing this filename.
<stream stream.mp4>
Feed feed.ffm
Format mp4
# Audio settings
NoAudio
# Video Settings
#VideoSize 1280x720 # Video resolution
#VideoFrameRate 30 # Video FPS
#AVOptionVideo flags +global_header # Parameters passed to encoder
#AVOptionVideo cpu-used 0
#AVOptionVideo qmin 10
#AVOptionVideo qmax 42
#AVOptionVideo quality good
PreRoll 0
StartSendOnKey
#VideoBitRate 400 # Video bitrate
</stream>
# Server status
<Stream stat.html>
Format status
# Only allow local people to get the status
ACL allow localhost
ACL allow 192.168.0.0 192.168.255.255
</Stream>
这是我通过命令行发出的命令和相应的输出：
$ ffmpeg -s 1280x720 -f video4linux2 -r 30 -vcodec h264 -re -i /dev/video0 \
-copyinkf -codec copy h**p://localhost:8090/feed.ffm
ffmpeg version N-67036-g04a4fb8 Copyright (c) 2000-2014 the FFmpeg developers
built on Oct 20 2014 17:39:50 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
configuration: --enable-gpl --enable-libx264
libavutil 54. 10.100 / 54. 10.100
libavcodec 56. 8.102 / 56. 8.102
libavformat 56. 9.101 / 56. 9.101
libavdevice 56. 1.100 / 56. 1.100
libavfilter 5. 2.100 / 5. 2.100
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Input #0, video4linux2,v4l2, from '/dev/video0':
Duration: N/A, start: 12614.859199, bitrate: N/A
Stream #0:0: Video: h264 (Constrained Baseline), yuvj420p(pc), 1280x720 [SAR 1:1 DAR 16:9], -5 kb/s, 30 fps, 30 tbr, 1000k tbn, 60 tbc
Output #0, ffm, to 'h**p://localhost:8090/feed.ffm':
Metadata:
creation_time : now
encoder : Lavf56.9.101
Stream #0:0: Video: h264, yuvj420p, 1280x720 [SAR 1:1 DAR 16:9], q=2-31, -5 kb/s, 30 fps, 1000k tbn, 30 tbc
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 0, current: -166263; changing to 1. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 1, current: -134365; changing to 2. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 2, current: -102381; changing to 3. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 3, current: -66434; changing to 4. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 4, current: -34548; changing to 5. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 5, current: -2645; changing to 6. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 232857, current: 138514; changing to 232858. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 232858, current: 167942; changing to 232859. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 232859, current: 197415; changing to 232860. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 232860, current: 227037; changing to 232861. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 997959, current: 938599; changing to 997960. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 997960, current: 995052; changing to 997961. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 1240745, current: 1232841; changing to 1240746. This may result in incorrect timestamps in the output file.
[ffm @ 0x28c7ea0] Non-monotonous DTS in output stream 0:0; previous: 1293561, current: 1282157; changing to 1293562. This may result in incorrect timestamps in the output file.
frame= 69 fps= 34 q=-1.0 Lsize= 912kB time=00:00:02.01 bitrate=3702.1kbits/s
例如，当我尝试使用 VLC 播放流时 - vlc h**p://localhost:8090/stream.mp4- 我收到以下错误：
[00007f5234003948]核心流错误：无法预填充缓冲区
我也无法在网络浏览器端观看流。
有人可以给我一个提示吗？
答案1
我一直在使用您的配置在我的 OpenWRT 路由器（TP-Link WDR3600，MIPS cpu，560 mHz）上使用 ffmpeg 和罗技 C920 摄像头。在 640x480 及以上分辨率下，我的系统无法可靠运行。我尝试单独启动 ffmpeg 而不进行转码（我的路由器根本无法进行任何转码，CPU 太弱）并使用 VLC 观看流：
ffmpeg -f v4l2 -input_format h264 -video_size 320x400 -i /dev/video0 -copyinkf -codec copy -f mpegts udp://192.168.1.100:20000
640x480 的视频会失真，800x600 或更高的分辨率根本不起作用，ffmpeg 会给出大量“非单调 DTS ...”消息。 320x400 就可以了。 MJPEG 视频输出效果更好，我能够以 1920x1080 和 15 fps 运行 C920，数据速率高于 50 Mbit/s，但 MJPEG 也不是 100% 无错误。看起来相机在 H264 上有一些问题，至少在 ffmpeg 上是这样。在 H264 下，无论我尝试设置哪种分辨率/帧速率，相机都能提供大约 3.2 Mbit/s 的恒定比特率。
但回到正题。为了让 h264 与 ffserver 一起工作，我修改了您的 Feed 部分，通过更改“Format”并注释掉“stream”部分中的 StartSendOnKey：
格式化 mpegt ... #StartSendOnKey
通过在“Feed”部分添加 ffmpeg“Launch”字符串：
启动 ffmpeg -f v4l2 -input_format h264 -video_size 320x400 -i /dev/video0 -copyinkf -codec 复制
并将 MaxBandwidth 更改为 50000
我使用vlc作为客户端软件。
答案2
我正在使用此配置，并且它运行良好 server.conf 文件：
HTTPPort 1235
RTSPPort 1234
HTTPBindAddress 0.0.0.0
MaxHTTPConnections 2000
MaxClients 1000
MaxBandwidth 100000
#CustomLog –
#########################################
## usb cam: logitec c920
#########################################
<Feed camfeed.ffm>
File /tmp/camfeed.ffm
FileMaxSize 500K
#allow only localhost to publish feed
ACL allow 192.168.1.149
</Feed>
<Stream usbcam.mov>
Feed camfeed.ffm
Format rtp
#cam defaults:
VideoSize 800x600
VideoFrameRate 24
VideoBitRate 400
VideoCodec libx264
NoLoop
NoAudio
Preroll 0
StartSendOnKey
</Stream>
######################################
# ffmpeg cmd:
######################################
# ffmpeg -y -s 800x600 -f video4linux2 -i /dev/video0 -c:v libx264 -tune zerolatency -an http://192.168.1.149:1235/camfeed.ffm