The AV pre-roll is the amount of time to buffer before showing the audio/video data stream. The defaults for recording and live views is 2.0 seconds. Less than 2.0 seconds may, for some camera streams, result in choppy playback. Streams without audio may play fine with 0 seconds of pre-roll. The range for the pre-roll is 0 to 10 seconds.
The audio sync adjusts the time at which the audio is played. For example, if you have a stream that is consistently playing audio too early by 1 second, set the audio sync to 1.0 second. Similarly, if audio is playing too late by 1 second, set the audio sync to -1.0 second. The range for audio sync is -5.0 to +5.0 seconds. It is rare that a camera needs help synchronizing audio to its video.
While both pre-roll and audio sync are used by the client, not CAMNET server, these are stored at the server in the camera's cam.cfg because the value needed is likely to be the same for each client. For proper playback sync with other cameras' recordings, the pre-roll should be the same for all cameras. For instance, playing the recordings of two cameras covering the same general area, the streams will not be synchronized because one view has a different pre-roll (say, the default 2 seconds) while the other has no pre-roll. The same applies to live views.
The bottom section of the Playback panel is used to configure how the stream is to be played at the client. All the settings are stored in the camnetsvcmgr.cbn file (in AppData).
A CamView is the view window next to each of the 20 CamBox buttons. The image shown in the CamView is gotten from the snapshot URI given in the Access panel. If possible, the snapshot URI provided in the Access panel should get the smallest available snapshot from the camera. The typical CamView window size varies by how large the Camnet Service Manager itself is, but 176x96 px is typically the maximum for a screen resolution of 1920x1200 @ 120 DPI. Camnet Service Manager uses Direct2D and DirectWrite; these scale perfectly as the main window is sized. It works as well on a 4k display as it does on a standard 1920x1200 display, and just as well on a 1280x800 tablet or a 1024x600 netbook.
The CamView mode and CamView rotate settings cannot be changed.
The CamView size offers three modes: native, auto, and autozoom. When CamView size is set to native, the JPEG snapshot as sent by the camera to CAMNET server is the same JPEG used to fill the CamView window. To have CAMNET server exactly size the snapshot JPEG to what CamView needs, select auto. To resize exactly as needed, plus zooming in a bit, and keeping the original aspect ratio, use autozoom.
The CamView rate at minimum results in getting another CamView snapshot JPEG from CAMNET server once every four seconds (0.25 FPS). Nominal gets another snapshot every second (1.0 FPS). Off won't get a snapshot.The snapshot sent by CAMNET server may be old, but no more than a few seconds. The reason for this is that some cameras are very slow to provide a snapshot, and almost always require a new connection (i.e., CAMNET server must reconnect to each camera for each snapshot, and some cameras can be very slow connecting). CAMNET server is out getting new snapshots before the client asks, and buffers it waiting for a client to get it. This way, the client doesn't have to wait for a snapshot, though the snapshot it gets may have been gotten a second or two before. Because some snapshots can take more than 1.0+ seconds to get -- HTTPS and digest authentication each require multiple exchanges, and the new connection itself -- it may not be possible to use a CamView rate of nominal (1 FPS). Some cameras can deliver a snapshot much faster: for example, the Trendnet TV-IP201 and Toshiba IKWB-15 return a shapshot in 0.02 seconds.The four Video fields affect the video stream for the client only. The original stream, such as that being recorded, or sent to other clients, is not affected by these values. CAMNET server is where the transcoding takes place, but it only occurs while the requesting-client is viewing the stream.
Video mode has two choices: native, which shows the stream in its native format, and H.264, which transcodes the camera stream to H.264. CAMNET server does the transcoding to H.264 (not the client). If the original stream is H.264 and Video mode is set to H.264, transcoding is still done, even if Video size and Video rotate are each set to native.
Video size offers four choices: native, 1/2, 1/4, and 1/8. Selecting other than native requires Video mode to be H.264.
When transcoding, the encoding bitrate used by the H.264 encoder is specified by setting Xcode bitrate. The suggested choices are: auto-hi, auto-med, auto-lo, 2.0, 1.0, 0.75, and 0.5 Mbps. Higher bitrates can provide better image quality. A high bitrate can also shift the encoder into a HiQ mode, which uses more GPU and/or CPU resources. Auto-hi usually works well. Using a bitrate too low can result in periodically-distorted video. Alternate values can be used: 1.5 Mbps could be entered, or 4.0 Mbps, for example. See Recordings, Stats (at 5L:), for how to specify HiQ mode for transcoding.
Video rotate has three choices: native, 90, and 270. Selecting other than native requires Video mode to be H.264. Rotating performs a perfect rotatation: if the frame dimensions were originally 1280 x 720, the rotated frame becomes 720 x 1280. CPU can be noticeable when rotating a 1920 x 1080 stream (to 1080 x 1920). To ease CPU use, set Video resize to 1/2 (to 540 x 960).While recordings are unaffected by transcoding (video format, resize, rotate), exporting a recording excerpt will use the transcoded output. For example, a recording that is in M-JPEG format, with Video mode set to H.264, will, when exported, create an .mp4 file with H.264 frames. Similarly, if Video rotate were set to 90, the excerpt would be of the rotated stream. The transcoding, and the export to .mp4, is done at CAMNET server. The client does nothing.Audio mode has three choices: mute, as-is, and on. Mute means audio output is muted by the client; the volume level is set to 0. As-is means not muted. On and as-is work identically.If the system mixer has muted the client the client produces no sound. Un-mute the client at the mixer for audio.
If the Cam setup, Access panel has Audio set to no, the Audio mode field always shows as disabled.
A peel-view window has an independent mute menu item in its system menu (it is stored in the .cbn so it is remembered the next time). If the Audio mode setting in the Playback panel is set to mute, the peel-view window for a camera is also muted for the duration of that peel view. To regain audio in new peel views, set Audio mode to on or as-is.
The Live view control panel has a Mute/Listen button. This affects the main view's audio, for both recording playback and for live view. If the button shows Mute, pressing it mutes the main window audio; if it shows Listen, pressing it un-mutes.
Use the Left channel, Right channel, and Master level settings to set the balance and master audio level. This affects the main and peel-view windows, for the audio of this camera only.