Bit Rate Filtering (b)

To filter out certain bit rates (to test a particular bit rate version, for example), add a b query string to the end of the publish URL. There are several usages:

  • Filter all bit rates except those specifically designated (and the lowest audio rate); the string takes the form:
    b=bitrate,bitrate,bitrate,...
    For example, if you have bit rates 200, 300, 700, and 1200, and you want to include only bit rates 200, 700, and the lowest audio rate, your URL would be as follows:
    uri/master.m3u8?b=200,700

    This produces only the 200 and 700 bit rate streams and the lowest audio bit rate.

  • Designate a bit rate range (in kbps) outside of which the stream or streams you wish to filter fall. The string format is:
    b=lower_end-upper_end
    For example, if you have bit rates 200, 300, 700, and 1200, and you want to include all bit rates at or greater than 200 and at or less than 700, your URL format is:
    uri/master.m3u8?b=200-700

    This produces the 200, 300, and 700 bit rate streams.

  • Designate the low end of a bit rate range (in kbps) where all bit rates below the value are filtered. The string format is:
    b=low_end-
    For example, if you have bit rates 200, 300, 700, and 1200, and you want to include all bit rates at and higher than 300 kbps, your URL format is:
    uri/master.m3u8?b=300-

    This produces the 300, 700, and 1200 bit rate streams.

  • Designate the high end of a bit rate range (in kbps) where all bit rates at and above the designation are filtered. The string format is:
    b=0-high_end
    For example, if you have bit rates 200, 300, 700, and 1200, and you want to include all bit rates lower than or equal to 700 kbps, your URL format is:
    uri/master.m3u8?b=0-700

    This produces the 200, 300, and 700 bit rate streams.

  • Any combination of the above.
    For example, if you have bit rates 200, 300, 700, 1200, and 1800, and you want to include all bit rates except 700, your URL format is:
    uri/master.m3u8?b=0-300,1200-

    This produces only the 200, 300, 1200, and 1800 bit rate streams and the lowest audio bit rate.

    Note:

    If Bit Rate Filtering and the Extracted Audio-Only features are simultaneously enabled, bit rate filtering is applied first, then audio-only extraction is applied to the remaining bit rates.

    After you specify the set-akamai-hls-revision query string to 4 or higher version (as described in Section HLS delivery improvements per HLS spec upgrade), you do not need to set up the Bit Rate Filtering query string. The quality of your streaming will be automatically corrected.