[FFmpeg-devel] [PATCH 2/4] Add a new hls_flag peak_segment_bw

[Amit Kale]

If this flag is set, BANDWIDTH value in a master playlist entry will be set to
the peak segment bandwidth.

Signed-off-by: Amit Kale <amitk at hotstar.com>
---
  doc/muxers.texi      |  4 ++++
  libavformat/hlsenc.c | 29 +++++++++++++++++++++--------
  2 files changed, 25 insertions(+), 8 deletions(-)

Index: ffmpeg/doc/muxers.texi
===================================================================
--- ffmpeg.orig/doc/muxers.texi
+++ ffmpeg/doc/muxers.texi
@@ -789,6 +789,10 @@ subdirectories.
  Possible values:
  
  @table @samp
+ at item peak_segment_bw
+If this flag is set, BANDWIDTH value in a master playlist entry will be
+set to the peak segment bandwidth.
+
  @item single_file
  If this flag is set, the muxer will store all segments in a single MPEG-TS
  file, and will use byte ranges in the playlist. HLS playlists generated with
Index: ffmpeg/libavformat/hlsenc.c
===================================================================
--- ffmpeg.orig/libavformat/hlsenc.c
+++ ffmpeg/libavformat/hlsenc.c
@@ -99,6 +99,7 @@ typedef enum HLSFlags {
      HLS_TEMP_FILE = (1 << 11),
      HLS_PERIODIC_REKEY = (1 << 12),
      HLS_INDEPENDENT_SEGMENTS = (1 << 13),
+    HLS_PEAK_SEGMENT_BW = (1 << 14),
  } HLSFlags;
  
  typedef enum {
@@ -1174,7 +1175,8 @@ static int64_t get_stream_bit_rate(AVStr
  }
  
  static int create_master_playlist(AVFormatContext *s,
-                                  VariantStream * const input_vs)
+                                  VariantStream * const input_vs,
+                                  int last)
  {
      HLSContext *hls = s->priv_data;
      VariantStream *vs, *temp_vs;
@@ -1191,13 +1193,16 @@ static int create_master_playlist(AVForm
          for (i = 0; i < hls->nb_varstreams; i++)
              if (!hls->var_streams[i].m3u8_created)
                  return 0;
-    } else {
+    } else if (!last) {
           /* Keep publishing the master playlist at the configured rate */
          if (&hls->var_streams[0] != input_vs || !hls->master_publish_rate ||
              input_vs->number % hls->master_publish_rate)
              return 0;
      }
  
+    if (hls->flags & HLS_PEAK_SEGMENT_BW && hls->version < 7)
+        hls->version = 7;
+
      set_http_options(s, &options, hls);
  
      ret = hlsenc_io_open(s, &hls->m3u8_out, hls->master_m3u8_url, &options);
@@ -1298,11 +1303,21 @@ static int create_master_playlist(AVForm
          }
  
          bandwidth = 0;
-        if (vid_st)
-            bandwidth += get_stream_bit_rate(vid_st);
-        if (aud_st)
-            bandwidth += get_stream_bit_rate(aud_st);
-        bandwidth += bandwidth / 10;
+        if (last && hls->flags & HLS_PEAK_SEGMENT_BW) {
+            HLSSegment *hs = vs->segments;
+            while (hs) {
+               int64_t segment_bandwidth = hs->size * 8 / hs->duration;
+                if (bandwidth < segment_bandwidth)
+                    bandwidth = segment_bandwidth;
+                hs = hs->next;
+            }
+        } else {
+            if (vid_st)
+                bandwidth += get_stream_bit_rate(vid_st);
+            if (aud_st)
+                bandwidth += get_stream_bit_rate(aud_st);
+            bandwidth += bandwidth / 10;
+        }
  
          ccgroup = NULL;
          if (vid_st && vs->ccgroup) {
@@ -1443,7 +1458,7 @@ fail:
          ff_rename(temp_filename, vs->m3u8_name, s);
  
      if (ret >= 0 && hls->master_pl_name)
-        if (create_master_playlist(s, vs) < 0)
+        if (create_master_playlist(s, vs, last) < 0)
              av_log(s, AV_LOG_WARNING, "Master playlist creation failed\n");
  
      return ret;
@@ -2819,6 +2834,7 @@ static const AVOption options[] = {
      {"fmp4",   "make segment file to fragment mp4 files in m3u8", 0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_TYPE_FMP4 }, 0, UINT_MAX,   E, "segment_type"},
      {"hls_fmp4_init_filename", "set fragment mp4 file init filename", OFFSET(fmp4_init_filename),   AV_OPT_TYPE_STRING, {.str = "init.mp4"},            0,       0,         E},
      {"hls_flags",     "set flags affecting HLS playlist and media file generation", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0 }, 0, UINT_MAX, E, "flags"},
+    {"peak_segment_bw",   "sets bandwidth in master play list to peak segment bandwidth", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_PEAK_SEGMENT_BW }, 0, UINT_MAX,   E, "flags"},
      {"single_file",   "generate a single media file indexed with byte ranges", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SINGLE_FILE }, 0, UINT_MAX,   E, "flags"},
      {"temp_file", "write segment to temporary file and rename when complete", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_TEMP_FILE }, 0, UINT_MAX,   E, "flags"},
      {"delete_segments", "delete segment files that are no longer part of the playlist", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_DELETE_SEGMENTS }, 0, UINT_MAX,   E, "flags"},