From 91b922856977a2c317925c6e6c6162b2ac9c97d4 Mon Sep 17 00:00:00 2001
From: chundonglinlin <chundonglinlin@163.com>
Date: Wed, 29 Jun 2022 09:47:57 +0800
Subject: [PATCH] HLS: parse exist m3u8 when stream publish.

---
 trunk/src/app/srs_app_hls.cpp | 136 +++++++++++++++++++++++++++++++++-
 1 file changed, 135 insertions(+), 1 deletion(-)

diff --git a/trunk/src/app/srs_app_hls.cpp b/trunk/src/app/srs_app_hls.cpp
index 3ae959897..f2ec18985 100644
--- a/trunk/src/app/srs_app_hls.cpp
+++ b/trunk/src/app/srs_app_hls.cpp
@@ -392,7 +392,8 @@ srs_error_t SrsHlsMuxer::restore_stream()
         return err;
     }
 
-    srs_trace("hls: restore stream m3u8=%s, m3u8_url=%s", m3u8.c_str(), m3u8_url.c_str());
+    srs_trace("hls: restore stream m3u8=%s, m3u8_url=%s, hls_path=%s",
+            m3u8.c_str(), m3u8_url.c_str(), hls_path.c_str());
 
     // read m3u8
     SrsFileReader fr;
@@ -408,7 +409,140 @@ srs_error_t SrsHlsMuxer::restore_stream()
     }
     fr.close();
 
+    std::string body = fbuf;
+
     // parse
+    if (body.empty()) {
+        return srs_error_wrap(err, "read empty m3u8");
+    }
+
+    int sequence_num = 0;
+    srs_utime_t max_target_duration = 0;
+    bool discon = false;
+
+    std::string ptl;
+    while (!body.empty()) {
+        size_t pos = string::npos;
+
+        std::string line;
+        if ((pos = body.find("\n")) != string::npos) {
+            line = body.substr(0, pos);
+            body = body.substr(pos + 1);
+        } else {
+            line = body;
+            body = "";
+        }
+
+        line = srs_string_replace(line, "\r", "");
+        line = srs_string_replace(line, " ", "");
+
+        // #EXT-X-VERSION:3
+        // the version must be 3.0
+        if (srs_string_starts_with(line, "#EXT-X-VERSION:")) {
+            if (!srs_string_ends_with(line, ":3")) {
+                srs_warn("m3u8 3.0 required, actual is %s", line.c_str());
+            }
+            continue;
+        }
+
+        // #EXT-X-PLAYLIST-TYPE:VOD
+        // the playlist type, vod or nothing.
+        if (srs_string_starts_with(line, "#EXT-X-PLAYLIST-TYPE:")) {
+            ptl = line;
+            continue;
+        }
+
+        // #EXT-X-MEDIA-SEQUENCE:4294967295
+        // the media sequence no.
+        if (srs_string_starts_with(line, "#EXT-X-MEDIA-SEQUENCE:")) {
+            sequence_num = ::atof(line.substr(string("#EXT-X-MEDIA-SEQUENCE:").length()).c_str());
+        }
+
+        // #EXT-X-TARGETDURATION:12
+        // the target duration is required.
+        if (srs_string_starts_with(line, "#EXT-X-TARGETDURATION:")) {
+            max_target_duration = ::atof(line.substr(string("#EXT-X-TARGETDURATION:").length()).c_str());
+        }
+
+        // #EXT-X-DISCONTINUITY
+        // the discontinuity tag.
+        if (srs_string_starts_with(line, "#EXT-X-DISCONTINUITY")) {
+            discon = true;
+        }
+
+        // #EXT-X-ENDLIST
+        // parse completed.
+        if (line == "#EXT-X-ENDLIST") {
+            break;
+        }
+
+        // #EXTINF:11.401,
+        // livestream-5.ts
+        // parse each ts entry, expect current line is inf.
+        if (!srs_string_starts_with(line, "#EXTINF:")) {
+            continue;
+        }
+
+        // expect next line is url.
+        std::string ts_url;
+        if ((pos = body.find("\n")) != string::npos) {
+            ts_url = body.substr(0, pos);
+            body = body.substr(pos + 1);
+        } else {
+            srs_warn("ts entry unexpected eof, inf=%s", line.c_str());
+            break;
+        }
+
+        // parse the ts duration.
+        line = line.substr(string("#EXTINF:").length());
+        if ((pos = line.find(",")) != string::npos) {
+            line = line.substr(0, pos);
+        }
+
+        double ts_duration = ::atof(line.c_str());
+
+        // load the default acodec from config.
+        SrsAudioCodecId default_acodec = SrsAudioCodecIdAAC;
+        if (true) {
+            std::string default_acodec_str = _srs_config->get_hls_acodec(req->vhost);
+            if (default_acodec_str == "mp3") {
+                default_acodec = SrsAudioCodecIdMP3;
+            } else if (default_acodec_str == "aac") {
+                default_acodec = SrsAudioCodecIdAAC;
+            } else if (default_acodec_str == "an") {
+                default_acodec = SrsAudioCodecIdDisabled;
+            } else {
+                srs_warn("hls: use aac for other codec=%s", default_acodec_str.c_str());
+            }
+        }
+
+        // load the default vcodec from config.
+        SrsVideoCodecId default_vcodec = SrsVideoCodecIdAVC;
+        if (true) {
+            std::string default_vcodec_str = _srs_config->get_hls_vcodec(req->vhost);
+            if (default_vcodec_str == "h264") {
+                default_vcodec = SrsVideoCodecIdAVC;
+            } else if (default_vcodec_str == "vn") {
+                default_vcodec = SrsVideoCodecIdDisabled;
+            } else {
+                srs_warn("hls: use h264 for other codec=%s", default_vcodec_str.c_str());
+            }
+        }
+
+        // new segment.
+        SrsHlsSegment* seg = new SrsHlsSegment(context, default_acodec, default_vcodec, writer);
+        seg->sequence_no = sequence_num++;
+        seg->set_path(hls_path + "/" + req->app + "/" + ts_url);
+        seg->uri = ts_url;
+        seg->set_sequence_header(discon);
+
+        seg->append(0);
+        seg->append(ts_duration * 1000);
+
+        segments->append(seg);
+
+        discon = false;
+    }
 
     return err;
 }