ZLKMedia/3rdpart/media-server/libhls/include/hls-param.h

#ifndef _hls_param_h_
#define _hls_param_h_

// https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/StreamingMediaGuide/FrequentlyAskedQuestions/FrequentlyAskedQuestions.html
// https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/StreamingMediaGuide/FrequentlyAskedQuestions/FrequentlyAskedQuestions.html
// 1. What kinds of encoders are supported?
// H.264 video and AAC audio (HE-AAC or AAC-LC).
// 2. What are the specifics of the video and audio formats supported?
// Video: H.264 Baseline Level 3.0, Baseline Level 3.1, Main Level 3.1, and High Profile Level 4.1.
// Audio: HE-AAC or AAC-LC up to 48 kHz, stereo audio
//        MP3 (MPEG-1 Audio Layer 3) 8 kHz to 48 kHz, stereo audio
//        AC-3 (for Apple TV, in pass-through mode only)

// 3. What duration should media files be?
// A duration of 10 seconds of media per file seems to strike a reasonable balance for most broadcast content.
// http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8
#define HLS_DURATION 10 // 10s, from Apple recommendation

// 4. How many files should be listed in the index file during a continuous, ongoing session?
// The normal recommendation is 3, but the optimum number may be larger.
#define HLS_LIVE_NUM 3

// HTTP Content-Type
// Playlist files whose names end in .m3u8 and/or have the HTTP Content-
// Type "application/vnd.apple.mpegurl" are encoded in UTF-8[RFC3629].
// Files whose names end with.m3u and/or have the HTTP Content-Type
// [RFC2616] "audio/mpegurl" are encoded in US-ASCII[US_ASCII].
#define HLS_M3U8_TYPE   "application/vnd.apple.mpegURL" 
#define HLS_M3U_TYPE	"audio/mpegurl"
#define HLS_TS_TYPE     "video/MP2T"

#define PTS_NO_VALUE INT64_MIN //(int64_t)0x8000000000000000L


// version: 1 (default)
//
// version: 2
//   The IV attribute of the EXT-X-KEY tag.
// version: 3
//   Floating-point EXTINF duration values.
// version: 4
//   The EXT-X-BYTERANGE tag.
//   The EXT-X-I-FRAMES-ONLY tag.
// version: 5
//   The KEYFORMAT and KEYFORMATVERSIONS attributes of the EXT-X-KEY tag.
//   The EXT-X-MAP tag.
// version: 6
//   The EXT-X-MAP tag in a Media playlist that does not contain EXT-X-I-FRAMES-ONLY.


// 6.2.2. Live Playlists
// 1. The server MUST NOT remove a media segment from the Playlist file if
//    the duration of the Playlist file minus the duration of the segment
//    is less than three times the target duration
// 2. When the server removes a media segment from the Playlist, the
//    corresponding media URI SHOULD remain available to clients for a
//    period of time equal to the duration of the segment plus the duration
//    of the longest Playlist file distributed by the server containing
//    that segment.

// 6.3.3. Playing the Playlist file
// 1. If the EXT-X-ENDLIST tag is not present, the client SHOULD NOT
//    choose a segment which starts less than three target durations from
//    the end of the Playlist file.
// 2. The client SHOULD attempt to load media segments in advance of when
//    they will be required for uninterrupted playback to compensate for
//    temporary variations in latency and throughput.
// 3. The client MUST be prepared to reset its parser(s) and decoder(s)
//    before playing a media segment that has an EXT-X-DISCONTINUITY tag
//    applied to it.

// 6.3.4. Reloading the Playlist file
// 1. The client MUST periodically reload the Media Playlist file unless it
//    contains the EXT-X-ENDLIST tag.
// 2. if Playlist file changed since the last time it was loaded, the client MUST wait for 
//    at least the target duration before attempting to reload the Playlist file again
// 3. if Playlist file not changed then it MUST wait for a period of one-half the target
//    duration before retrying

#endif /* !_hls_param_h_ */