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decoder_priority=OPENH264,FF

7. Restart WCS.

Lowering multithreaded encoding threshold

By default, multithreaded encoding is enabled for 720p and higher profiles. Sometimes it is necessary to lower this threshold to encode 480p streams also in two and more threads

video_encoder_second_thread_threshold=408950

Reducing memory allocations for decoding

To reduce memory allocations for decoding, since build 5.2.559 the ability to use buffer pools for decoded pictures is added. The feature can be enabled with the following parameter

decoder_buffer_pool=true

In this case, a pool of buffers will be allocated for every incoming picture resolution. When buffer is not needed any more, it is not deleted, but returned to pool. To get memory usage information, statistic collection should be enabled with the following parameter

decoder_buffer_pool_stats=true

Statistic is available by the following query (JSON format only)

curl -s 'http://localhost:8081/?action=stat&format=json&groups=decoder_buffer_pool_stats'

and grouped by pools

{
  "decoder_buffer_pool_stats": {
    "decoder_buffer_pool_info": {
      "decoder_buffer_pool_info_pools": {
        "3072x1536": {
          "decoder_buffer_pool_width": 3072,
          "decoder_buffer_pool_height": 1536,
          "decoder_buffer_pool_size_bytes": 84934656,
          "decoder_buffer_pool_leased": 6,
          "decoder_buffer_pool_allocated": 12
        },
        "1280x720": {
          "decoder_buffer_pool_width": 1280,
          "decoder_buffer_pool_height": 720,
          "decoder_buffer_pool_size_bytes": 688584704,
          "decoder_buffer_pool_leased": 0,
          "decoder_buffer_pool_allocated": 3605
        }
      },
      "decoder_buffer_pool_total_size_bytes": 773519360
    }
  }
}

Where

• decoder_buffer_pool_total_size_bytes - total memory size allocated to all the pools in bytes
• decoder_buffer_pool_width - pool picture width
• decoder_buffer_pool_height - pool picture height
• decoder_buffer_pool_size_bytes - memory size allocated to the pool in bytes
• decoder_buffer_pool_leased - buffers used count in the pool
• decoder_buffer_pool_allocated - buffers allocated ciunt in the pool

The memory allocated to buffers unused can be freed by /debug/decoder/shrink_buffer_provider_pools REST API query

Freeing the memory allocated to buffers unused

REST query should be HTTP/HTTPS POST request as follows:

• HTTP: http://test.flashphoner.com:8081/rest-api/debug/decoder/shrink_buffer_provider_pools
• HTTPS: https://test.flashphoner.com:8444/rest-api/debug/decoder/shrink_buffer_provider_pools

Where:

• test.flashphoner.com - WCS server address
• 8081 - standard REST / HTTP port of WCS server
• 8444 - standard HTTPS port
• rest-api - URL mandatory part
• /cdn/profile/print - REST query used

REST queries should be sent to Edge server.

Stream transcoding by two or more profiles with the same video parameters

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