[FFmpeg-cvslog] avformat/hlsenc: support CODECS Attribute in hevc EXT-X-STREAM-INF

[Steven Liu]

ffmpeg | branch: master | Steven Liu <lq at chinaffmpeg.org> | Tue Oct 13 15:05:59 2020 +0800| [a2b1dd0ce301450a47c972745a6b33c4c273aa5d] | committer: liuqi05

avformat/hlsenc: support CODECS Attribute in hevc EXT-X-STREAM-INF

fix ticket: 8904
parse the SPS from extradata and get profile_tier_level
write the profile_tier_level info into CODECS Attribute

HLS CODECS Attribute reference to :https://developer.apple.com/documentation/http_live_streaming/hls_authoring_specification_for_apple_devices/hls_authoring_specification_for_apple_devices_appendixes

Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
Signed-off-by: liuqi05 <liuqi05 at kuaishou.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a2b1dd0ce301450a47c972745a6b33c4c273aa5d
---

 libavformat/hlsenc.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index f7eb2411b0..8e4cc36d50 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -46,6 +46,7 @@
 
 #include "avformat.h"
 #include "avio_internal.h"
+#include "avc.h"
 #if CONFIG_HTTP_PROTOCOL
 #include "http.h"
 #endif
@@ -337,6 +338,49 @@ static void write_codec_attr(AVStream *st, VariantStream *vs)
         } else {
             goto fail;
         }
+    } else if (st->codecpar->codec_id == AV_CODEC_ID_HEVC) {
+        uint8_t *data = st->codecpar->extradata;
+        int profile = FF_PROFILE_UNKNOWN;
+        int level = FF_LEVEL_UNKNOWN;
+
+        if (st->codecpar->profile != FF_PROFILE_UNKNOWN)
+            profile = st->codecpar->profile;
+        if (st->codecpar->level != FF_LEVEL_UNKNOWN)
+            level = st->codecpar->level;
+
+        /* check the boundary of data which from current position is small than extradata_size */
+        while (data && (data - st->codecpar->extradata + 5) < st->codecpar->extradata_size) {
+            /* get HEVC SPS NAL and seek to profile_tier_level */
+            if (!(data[0] | data[1] | data[2]) && data[3] == 1 && ((data[4] & 0x42) == 0x42)) {
+                int remain_size = 0;
+                int rbsp_size = 0;
+                /* skip start code + nalu header */
+                data += 6;
+                /* process by reference General NAL unit syntax */
+                remain_size = st->codecpar->extradata_size - (data - st->codecpar->extradata);
+                uint8_t *rbsp_buf = ff_nal_unit_extract_rbsp(data, remain_size, &rbsp_size, 0);
+                if (!rbsp_buf)
+                    return;
+                if (rbsp_size < 13) {
+                    av_freep(&rbsp_buf);
+                    break;
+                }
+                /* skip sps_video_parameter_set_id   u(4),
+                 *      sps_max_sub_layers_minus1    u(3),
+                 *  and sps_temporal_id_nesting_flag u(1) */
+                profile = rbsp_buf[1] & 0x1f;
+                /* skip 8 + 8 + 32 + 4 + 43 + 1 bit */
+                level = rbsp_buf[12];
+                av_freep(&rbsp_buf);
+                break;
+            }
+            data++;
+        }
+        if (st->codecpar->codec_tag == MKTAG('h','v','c','1') &&
+            profile != FF_PROFILE_UNKNOWN &&
+            level != FF_LEVEL_UNKNOWN) {
+            snprintf(attr, sizeof(attr), "%s.%d.4.L%d.B01", av_fourcc2str(st->codecpar->codec_tag), profile, level);
+        }
     } else if (st->codecpar->codec_id == AV_CODEC_ID_MP2) {
         snprintf(attr, sizeof(attr), "mp4a.40.33");
     } else if (st->codecpar->codec_id == AV_CODEC_ID_MP3) {
@@ -2247,6 +2291,10 @@ static int hls_write_header(AVFormatContext *s)
                 continue;
             }
             avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits, inner_st->time_base.num, inner_st->time_base.den);
+            if (outer_st->codecpar->codec_id == AV_CODEC_ID_HEVC &&
+                outer_st->codecpar->codec_tag != MKTAG('h','v','c','1')) {
+                av_log(s, AV_LOG_WARNING, "Stream HEVC is not hvc1, you should use tag:v hvc1 to set it.\n");
+            }
             write_codec_attr(outer_st, vs);
 
         }