[FFmpeg-cvslog] Improve hls VOD mode hls performance problem.

Ronak Patel git at videolan.org
Sun Aug 19 05:00:50 EEST 2018


ffmpeg | branch: master | Ronak Patel <ronak2121 at yahoo.com> | Sun Aug 19 09:57:44 2018 +0800| [223d2bde22ce33dcbcb6f17f234b609cb98f1fb6] | committer: Steven Liu

Improve hls VOD mode hls performance problem.

This fixes the creation of the hls manifest in hlsenc.c by writing the
entire manifest at the end for VOD playlists. Live & Event Playlists are unaffected.
This also fixes the behavior with HLS_TEMP_FILE to work correctly when
-hlsflags temp_file is specified, instead of always relying on use_rename, which caused these problems.

Files that would previously take over a week to fragment now take
1 minute on the same hardware. This was a 153 hour audio file (2.2GB of audio).

Signed-off-by: Ronak Patel <ronak2121 at yahoo.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=223d2bde22ce33dcbcb6f17f234b609cb98f1fb6
---

 libavformat/hlsenc.c | 44 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 33 insertions(+), 11 deletions(-)

diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index b5644f05c4..43e6fc86c6 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -1374,7 +1374,7 @@ static int hls_window(AVFormatContext *s, int last, VariantStream *vs)
     char temp_filename[1024];
     int64_t sequence = FFMAX(hls->start_sequence, vs->sequence - vs->nb_entries);
     const char *proto = avio_find_protocol_name(s->url);
-    int use_rename = proto && !strcmp(proto, "file");
+    int use_temp_file = proto && !strcmp(proto, "file") && (s->flags & HLS_TEMP_FILE);
     static unsigned warned_non_file;
     char *key_uri = NULL;
     char *iv_string = NULL;
@@ -1397,11 +1397,11 @@ static int hls_window(AVFormatContext *s, int last, VariantStream *vs)
         hls->version = 7;
     }
 
-    if (!use_rename && !warned_non_file++)
+    if (!use_temp_file && !warned_non_file++)
         av_log(s, AV_LOG_ERROR, "Cannot use rename on non file protocol, this may lead to races and temporary partial files\n");
 
     set_http_options(s, &options, hls);
-    snprintf(temp_filename, sizeof(temp_filename), use_rename ? "%s.tmp" : "%s", vs->m3u8_name);
+    snprintf(temp_filename, sizeof(temp_filename), use_temp_file ? "%s.tmp" : "%s", vs->m3u8_name);
     if ((ret = hlsenc_io_open(s, &hls->m3u8_out, temp_filename, &options)) < 0)
         goto fail;
 
@@ -1472,7 +1472,7 @@ fail:
     av_dict_free(&options);
     hlsenc_io_close(s, &hls->m3u8_out, temp_filename);
     hlsenc_io_close(s, &hls->sub_m3u8_out, vs->vtt_m3u8_name);
-    if (ret >= 0 && use_rename)
+    if (use_temp_file)
         ff_rename(temp_filename, vs->m3u8_name, s);
 
     if (ret >= 0 && hls->master_pl_name)
@@ -1488,6 +1488,8 @@ static int hls_start(AVFormatContext *s, VariantStream *vs)
     AVFormatContext *oc = vs->avf;
     AVFormatContext *vtt_oc = vs->vtt_avf;
     AVDictionary *options = NULL;
+    const char *proto = avio_find_protocol_name(s->url);
+    int use_temp_file = proto && !strcmp(proto, "file") && (s->flags & HLS_TEMP_FILE);
     char *filename, iv_string[KEYSIZE*2 + 1];
     int err = 0;
 
@@ -1583,7 +1585,7 @@ static int hls_start(AVFormatContext *s, VariantStream *vs)
 
     set_http_options(s, &options, c);
 
-    if (c->flags & HLS_TEMP_FILE) {
+    if (use_temp_file) {
         char *new_name = av_asprintf("%s.tmp", oc->url);
         if (!new_name)
             return AVERROR(ENOMEM);
@@ -2145,6 +2147,8 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
     int ret = 0, can_split = 1, i, j;
     int stream_index = 0;
     int range_length = 0;
+    const char *proto = avio_find_protocol_name(s->url);
+    int use_temp_file = proto && !strcmp(proto, "file") && (s->flags & HLS_TEMP_FILE);
     uint8_t *buffer = NULL;
     VariantStream *vs = NULL;
     AVDictionary *options = NULL;
@@ -2214,10 +2218,10 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
 
     }
 
+    char *old_filename = NULL;
     if (vs->packets_written && can_split && av_compare_ts(pkt->pts - vs->start_pts, st->time_base,
                                                           end_pts, AV_TIME_BASE_Q) >= 0) {
         int64_t new_start_pos;
-        char *old_filename = NULL;
         int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);
 
         av_write_frame(vs->avf, NULL); /* Flush any buffered data */
@@ -2253,11 +2257,13 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
                 hlsenc_io_close(s, &vs->vtt_avf->pb, vs->vtt_avf->url);
             }
         }
-        if ((hls->flags & HLS_TEMP_FILE) && oc->url[0]) {
+
+        // look to rename the asset name
+        if (use_temp_file && oc->url[0]) {
             if (!(hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size <= 0))
-                if ((vs->avf->oformat->priv_class && vs->avf->priv_data) && hls->segment_type != SEGMENT_TYPE_FMP4)
+                if ((vs->avf->oformat->priv_class && vs->avf->priv_data) && hls->segment_type != SEGMENT_TYPE_FMP4) {
                     av_opt_set(vs->avf->priv_data, "mpegts_flags", "resend_headers", 0);
-            hls_rename_temp_file(s, oc);
+                }
         }
 
         if (vs->fmp4_init_mode) {
@@ -2286,6 +2292,17 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
                     return ret;
                 }
                 ff_format_io_close(s, &vs->out);
+
+                // rename that segment from .tmp to the real one
+                if (use_temp_file && oc->url[0]) {
+                    hls_rename_temp_file(s, oc);
+                    av_free(old_filename);
+                    old_filename = av_strdup(vs->avf->url);
+
+                    if (!old_filename) {
+                        return AVERROR(ENOMEM);
+                    }
+                }
             }
         }
 
@@ -2334,10 +2351,12 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
             return ret;
         }
 
-        if (!vs->fmp4_init_mode || byterange_mode)
+        // if we're building a VOD playlist, skip writing the manifest multiple times, and just wait until the end
+        if (hls->pl_type != PLAYLIST_TYPE_VOD) {
             if ((ret = hls_window(s, 0, vs)) < 0) {
                 return ret;
             }
+        }
     }
 
     vs->packets_written++;
@@ -2352,6 +2371,8 @@ static int hls_write_trailer(struct AVFormatContext *s)
     AVFormatContext *oc = NULL;
     AVFormatContext *vtt_oc = NULL;
     char *old_filename = NULL;
+    const char *proto = avio_find_protocol_name(s->url);
+    int use_temp_file = proto && !strcmp(proto, "file") && (s->flags & HLS_TEMP_FILE);
     int i;
     int ret = 0;
     VariantStream *vs = NULL;
@@ -2394,7 +2415,8 @@ failed:
             if (hls->segment_type != SEGMENT_TYPE_FMP4)
                 ff_format_io_close(s, &oc->pb);
 
-            if ((hls->flags & HLS_TEMP_FILE) && oc->url[0]) {
+            // rename that segment from .tmp to the real one
+            if (use_temp_file && oc->url[0] && !(hls->flags & HLS_SINGLE_FILE)) {
                 hls_rename_temp_file(s, oc);
                 av_free(old_filename);
                 old_filename = av_strdup(vs->avf->url);



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