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DirectShow RTMP Network Renderer & Writer

Purpose​

Writing RTMP compatible video/audio streams over a network connection

  • Supported Architectures: Microsoft DirectShow, Windows
  • Supported Formats: H.264 Video + AAC Audio

Module / Version​

nanocosmos RTMP Network Writer nRtmpRenderer.ax Version 3.0.3.1

DirectShow Connectivity​

The RTMP Writer is implemented as a “Renderer Filter”, which means it only has 2 input pins for compressed video and audio and no output pin. The input is accepting connections matching the following media types:

  1. Pin 1 Media Types:
  • MEDIATYPE_Video Pin 1 Media Subtypes: FourCCs: H264, h264

  • Pin 1 Formats:

    FORMAT_MPEG2_VIDEO, FORMAT_NONE

  • Pin 2 Major Media Types:

    MEDIATYPE_Audio

  • Pin 2 Media Subtypes:

    MEDIASUBTYPE_AAC, FourCC: 0x000000FF

  • Pin 2 Formats:

    FORMAT_WaveFormatEx, FORMAT_NONE

rtmp_writer_prop

The filter's property page offers a subset of encoding parameters, containing the most important options. URL formatting:rtmp: [hostname / IP address]/[application]+[stream name] for example:

rtmp:127.0.0.1/live+myStream with:IP address: 127.0.0.1 Application name: live, Stream name: myStream

Configuration​

The configuration may be set by using either the property page or the COM-Interface IRTMPOptions as declared in header file RTMPWriterOptions.h.

// Filter Guids
// {B4FB59C5-983B-4d96-9204-F8B0E46704EE}
DEFINE_GUID(CLSID_NANO_RTMP_WRITER,  0xb4fb59c5, 0x983b, 0x4d96, 0x92, 0x4, 0xf8, 0xb0, 0xe4, 0x67, 0x4, 0xee);

// Property Page GUID
// {EFC673DE-E20E-4699-8331-9522C5DF7A6D}
DEFINE_GUID(CLSID_NANO_RTMP_WRITER_PROPPAGE, 0xefc673de, 0xe20e, 0x4699, 0x83, 0x31, 0x95, 0x22, 0xc5, 0xdf, 0x7a, 0x6d);

// Configuration Interface GUID
// IID_IRTMPOptions interface
// {B8AF4593-BE31-449c-8485-3E6D65CBC1FE}
DEFINE_GUID(IID_IRTMPOptions, 0xb8af4593, 0xbe31, 0x449c, 0x84, 0x85, 0x3e, 0x6d, 0x65, 0xcb, 0xc1, 0xfe)

The streaming url can be set by using standard DirectShow interface IFileSinkFilter .

Configuration with DirectShow filter property page​

RTMP Writer Properties

The filter's property page offers a subset of encoding parameters, containing the most important options.

URL formatting:

rtmp:// [hostname / IP address]/[application]+[stream name]

for example: rtmp://127.0.0.1/live+myStream

with: IP address: 127.0.0.1 Application name: live, Stream name: myStream

Connection Test​

Connect/Disconnect buttons. Allows to connect before starting the graph and disconnect during the streaming (this stops the running graph).

RTMP Authentication​

RTMP Authentication expects a user name and a password for unlocking access to the Media Server. RTMP Authentication is an outdated functionality not available with nanoStream Cloud.

Automatic Reconnection:​

Attempts to restore network connection after n seconds to the server in case of network interrupts. During the reconnect attempts the graph still playing. 0 means no attempts to reconnect to server.

Advanced Configuration Options​

The advanced options should be handled carefully. They can severely affect network and streaming performance. Contact support if you want to fine tune any settings. Buffering: Data Flow: RTMP multiplexed data → application buffer → socket buffer → network. There are 2 buffer types:

  1. Socket level buffer: Size of the network socket buffer, much dependent on the underlying network architecture
  2. Application level buffer (Output Buffer Size, Output packet size), 0=no buffer Affects bandwidth utilization, prevents bitrate changes and puts the sending process to a separate thread.

Advanced Settings​

  • Live Mode: Turns on/off blocking of input pins. (should be off by default)
  • TCP No Delay: Activates the TCP_NODELAY option for TCP transmission ("Nagle Algorithm")
  • Timecode Options: Sends Time Code in RTMP Meta Data
  • Allow B Frames: should be on, it reduces the buffer/delay in H.264 Main Profile without B Frames. No effect in Baseline Mode.
  • Timecode Options: send Time Code in RTMP Meta Data

Connection Status Notification​

There are two possibilities to get the status of the connection to the server:

  • Event messages are sent via IMediaEventSink with the event code EC_NANO_RTMP_WRITER_STATUS declared in RTMPWriterOptions.h (#define EC_NANO_RTMP_WRITER_STATUS EC_USER+181). A message is sent when the connection state changes. The different states are represented by (also declared in RTMPWriterOptions.h):
  • RTMPWriterConnected=0
  • RTMPWriterDisconnected=1
  • RTMPWriterReconnecting=2
  • Using a callback function, which is called when the connection state changes:
    • Query for the interface IRTMPStatusNotify
    • Set the callback function via SetStatusNotifyHandler()

Rtmp Writer Filter crashes when using SetStatusNotifyHandler()​

This problem is probably caused by calling a function declared with one calling convention with a function pointer declared with a different calling convention. Here is a good explanation of the problem: Visual Studio Runtime Error

Run Time Check Failure

Conclusion: Make sure you use stdcall in your declaration

Log / Debug Configuration Registry Settings​

Key: HKEYCURRENTUSER\Software\DebugNano\ nRtmpRenderer.ax

File name​

Sets the output file name. The folder must exist. Value name: LogToFile Value type: REG_SZ / String Valid values: a valid output file name to enable file logging or an empty string

Logging level​

  • A higher value increases the amount of logging messages sent, and messages get more detailed.
  • Value name: TRACE
  • Value type: REG_DWORD
  • Valid values: 0 (minimal logging) - 9 (maximal logging)
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