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

[Steven Liu]

fix ticket: 8904
parse the SPS from extradata and get profile_tier_level
write the profile_tier_level info into 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>
---
 libavformat/hlsenc.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index cb31d6aed7..574d9f81e9 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -337,6 +337,43 @@ 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 i = 0;
+        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;
+
+        while (data && (data - st->codecpar->extradata) < st->codecpar->extradata_size) {
+            /* get HEVC SPS NAL and seek to profile_tier_level */
+            if (data && (data[0] | data[1] | data[2]) == 0 && data[3] == 1 && ((data[4] & 0x42) == 0x42)) {
+                int rbsp_byte_size;
+                data += 7;
+                /* process by reference General NAL unit syntax */
+                profile = *data & 0x1f;
+                rbsp_byte_size = st->codecpar->extradata_size - (data - st->codecpar->extradata);
+                for (i = 0; i < rbsp_byte_size; i++, data++) {
+                    if (data[0] == 0 && data[1] == 0 && data[2] == 3) {
+                        data += 2;
+                        i++;
+                    }
+                    /* skip 8 + 32 + 4 + 43 + 1 bit */
+                    if (i == 11)
+                        level = *data;
+                }
+                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 +2284,10 @@ 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);
 
         }
-- 
2.25.0