201707221 Release Note

The headline features of software update 201707222 are:

Updates the version of ffmpeg in use

Adds MPEG transmission (with sound) and streaming from the EasyCap

Configures video devices so that EasyCap can always be connected

Automatically determines video device address

Implements auto or manual switching of audio source

Displays viewfinder in CAMMPEG-2 mode every time

Implements correct PIDs for MPEG-2 modes

Optional callsign caption in MPEG-2 modes

The implications of some of these changes are major:

Updates the version of ffmpeg in use

The latest version of the ffmpeg video encoding software has been added. This is used to encode the video in MPEG-2 transmission modes and in the streaming modes. It just does more stuff better!

Adds MPEG transmission (with sound) and streaming from the EasyCap

Previously, MPEG-2 transmissions were only available from the RPi Camera, accompanied with sound from a USB audio dongle. This update adds the ability to transmit MPEG-2 from the EasyCap video input accompanied by sound from a microphone or the stereo line inputs on the EasyCap dongle. This mode is not yet perfect, and has the following limitations:

- There is no viewfinder in the AnalogMPEG-2 mode, just as there was no viewfinder in the Analog H264 mode. - Performance is poor at below 1MS. The mode is designed for use at 1MS or higher, although with slow-moving pictures it is usable at 333KS (just). - Some picture interference (a bit like ignition noise on old AM TVs) occurs with the Fushicai EasyCap dongle as sold by the BATC. This appears to be a complex driver issue. - Some sound interference (regular clicks) occurs on the UVC EasyCap dongles. - Other EasyCap dongles have yet to be tested. - Streaming to the BATC Website appears to work, but has not been extensively tested.

Configures video devices so that EasyCap can always be connected

Previously, if an EasyCap was connected for use in Analog mode, it had to be disconnected for CAMMPEG-2 mode. This is no longer the case and you can permanently connect the EasyCap for all modes. The functionality has been tested for Fushicai and UVC dongles, but should also work for EM28xx and STK1160 variants. Please post on the fiorum if the functionality does not work for your dongle. EasyCaps can be hot-plugged after the RPi has booted; the PRPi Camera cannot - it must be connected (or disconnected) before boot.

Automatically determines video device address

Previously, you had to enter the video device address as /dev/video0 or /dev/video1. Now if you enter "auto" in the text field it will automatically determine the correct address.

Implements auto or manual switching of audio source

There are now 5 audio modes: mic, EasyCap, auto, bleeps or no_audio. If you select auto, then the USB dongle microphone will be selected when your video source is the RPi Camera, and the EasyCap stereo line inputs will be connected when the EasyCap is your video source. Selection of mic will always select the USB microphone, and selection of EasyCap will always select the stereo line inputs. Selection of bleeps brings up the familiar bleeps.

Full details

This functionality relies on identifying audio and video device names. If it does not work for your particular devices, please post details (particularly the results of issuing the command "arecord -l") on the forum.

Full details of the audio switching logic are here Audio Switching.

Displays viewfinder in CAMMPEG-2 mode every time

The previous behaviour where the CAMMPEG-2 viewfinder did not appear on the first transmission after boot has been corrected.

Implements correct PIDs for MPEG-2 modes

You can now set the PMT, Video and Audio PIDs for MPEG-2 transmissions from the Console. The PCR PID is set to be the same as the Video PID. If no audio stream is transmitted, MiniTioune reports the audio PID as 4095 and requires a PID rescan (after a transmission with a valid audio PID) before it will display the video.

For H264 transmissions, the behaviour is different (and changed from previous versions): The Video PID can be set in the console and the PMT PID is automatically set to be Video PID-1. The Audio PID for the non-existent audio is set to Video PID-1, and the PCR PID is set the same as the Video PID.

Optional callsign caption in MPEG-2 modes

You can overlay a callsign caption on MPEG-2 transmissions by selecting it on from the touchscreen Menu 2 or the console output menu. There is no callsign caption on the streamed pictures (yet).

G8GKQ 25 July 2017.