[FFmpeg-devel] [PATCH v6 1/3] avformat/hlsenc:addition of #EXT-X-MEDIA tag and AUDIO attribute

Steven Liu lq at chinaffmpeg.org
Thu Dec 14 16:51:31 EET 2017




> 在 2017年12月14日,下午6:52,vdixit at akamai.com 写道:
> 
> From: Vishwanath Dixit <vdixit at akamai.com>
> 
> ---
> doc/muxers.texi           | 12 +++++++++
> libavformat/dashenc.c     |  3 ++-
> libavformat/hlsenc.c      | 62 ++++++++++++++++++++++++++++++++++++++++++++---
> libavformat/hlsplaylist.c |  4 ++-
> libavformat/hlsplaylist.h |  2 +-
> 5 files changed, 77 insertions(+), 6 deletions(-)
> 
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index 3d0c7bf..93db549 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -834,6 +834,18 @@ be a video only stream with video bitrate 1000k, the second variant stream will
> be an audio only stream with bitrate 64k and the third variant stream will be a
> video only stream with bitrate 256k. Here, three media playlist with file names
> out_1.m3u8, out_2.m3u8 and out_3.m3u8 will be created.
> + at example
> +ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k  \
> +  -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
> +  -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
> +  -master_pl_name master.m3u8 \
> +  http://example.com/live/out.m3u8
> + at end example
> +This example creates two audio only and two video only variant streams. In
> +addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
> +playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
> +and they are mapped to the two video only variant streams with audio group names
> +'aud_low' and 'aud_high'.
> 
> By default, a single hls variant containing all the encoded streams is created.
> 
> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
> index 5687530..f363418 100644
> --- a/libavformat/dashenc.c
> +++ b/libavformat/dashenc.c
> @@ -759,7 +759,8 @@ static int write_manifest(AVFormatContext *s, int final)
>             char playlist_file[64];
>             AVStream *st = s->streams[i];
>             get_hls_playlist_name(playlist_file, sizeof(playlist_file), NULL, i);
> -            ff_hls_write_stream_info(st, out, st->codecpar->bit_rate, playlist_file);
> +            ff_hls_write_stream_info(st, out, st->codecpar->bit_rate,
> +                    playlist_file, NULL);
>         }
>         avio_close(out);
>         if (use_rename)
> diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
> index fdf614b..273dd8a 100644
> --- a/libavformat/hlsenc.c
> +++ b/libavformat/hlsenc.c
> @@ -144,6 +144,7 @@ typedef struct VariantStream {
>     AVStream **streams;
>     unsigned int nb_streams;
>     int m3u8_created; /* status of media play-list creation */
> +    char *agroup; /* audio group name */
>     char *baseurl;
> } VariantStream;
> 
> @@ -1081,7 +1082,7 @@ static int create_master_playlist(AVFormatContext *s,
>                                   VariantStream * const input_vs)
> {
>     HLSContext *hls = s->priv_data;
> -    VariantStream *vs;
> +    VariantStream *vs, *temp_vs;
>     AVStream *vid_st, *aud_st;
>     AVIOContext *master_pb = 0;
>     AVDictionary *options = NULL;
> @@ -1115,6 +1116,34 @@ static int create_master_playlist(AVFormatContext *s,
> 
>     ff_hls_write_playlist_version(master_pb, hls->version);
> 
> +    /* For audio only variant streams add #EXT-X-MEDIA tag with attributes*/
> +    for (i = 0; i < hls->nb_varstreams; i++) {
> +        vs = &(hls->var_streams[i]);
> +
> +        if (vs->has_video || vs->has_subtitle || !vs->agroup)
> +            continue;
> +
> +        m3u8_name_size = strlen(vs->m3u8_name) + 1;
> +        m3u8_rel_name = av_malloc(m3u8_name_size);
> +        if (!m3u8_rel_name) {
> +            ret = AVERROR(ENOMEM);
> +            goto fail;
> +        }
> +        av_strlcpy(m3u8_rel_name, vs->m3u8_name, m3u8_name_size);
> +        ret = get_relative_url(hls->master_m3u8_url, vs->m3u8_name,
> +                               m3u8_rel_name, m3u8_name_size);
> +        if (ret < 0) {
> +            av_log(s, AV_LOG_ERROR, "Unable to find relative URL\n");
> +            goto fail;
> +        }
> +
> +        avio_printf(master_pb, "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"group_%s\"",
> +                vs->agroup);
> +        avio_printf(master_pb, ",NAME=\"audio_0\",DEFAULT=YES,URI=\"%s\"\n",
> +                m3u8_rel_name);
> +        av_freep(&m3u8_rel_name);
> +    }
> +
>     /* For variant streams with video add #EXT-X-STREAM-INF tag with attributes*/
>     for (i = 0; i < hls->nb_varstreams; i++) {
>         vs = &(hls->var_streams[i]);
> @@ -1147,6 +1176,25 @@ static int create_master_playlist(AVFormatContext *s,
>             continue;
>         }
> 
> +        /**
> +         * Traverse through the list of audio only rendition streams and find
> +         * the rendition which has highest bitrate in the same audio group
> +         */
> +        if (vs->agroup) {
> +            for (j = 0; j < hls->nb_varstreams; j++) {
> +                temp_vs = &(hls->var_streams[j]);
> +                if (!temp_vs->has_video && !temp_vs->has_subtitle &&
> +                    temp_vs->agroup &&
> +                    !strcmp(temp_vs->agroup, vs->agroup)) {
> +                    if (!aud_st)
> +                        aud_st = temp_vs->streams[0];
> +                    if (temp_vs->streams[0]->codecpar->bit_rate >
> +                            aud_st->codecpar->bit_rate)
> +                        aud_st = temp_vs->streams[0];
> +                }
> +            }
> +        }
> +
>         bandwidth = 0;
>         if (vid_st)
>             bandwidth += vid_st->codecpar->bit_rate;
> @@ -1154,7 +1202,8 @@ static int create_master_playlist(AVFormatContext *s,
>             bandwidth += aud_st->codecpar->bit_rate;
>         bandwidth += bandwidth / 10;
> 
> -        ff_hls_write_stream_info(vid_st, master_pb, bandwidth, m3u8_rel_name);
> +        ff_hls_write_stream_info(vid_st, master_pb, bandwidth, m3u8_rel_name,
> +                aud_st ? vs->agroup : NULL);
> 
>         av_freep(&m3u8_rel_name);
>     }
> @@ -1508,6 +1557,7 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
>     /**
>      * Expected format for var_stream_map string is as below:
>      * "a:0,v:0 a:1,v:1"
> +     * "a:0,agroup:a0 a:1,agroup:a1 v:0,agroup:a0  v:1,agroup:a1"
>      * This string specifies how to group the audio, video and subtitle streams
>      * into different variant streams. The variant stream groups are separated
>      * by space.
> @@ -1516,6 +1566,7 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
>      * respectively. Allowed values are 0 to 9 digits (limited just based on
>      * practical usage)
>      *
> +     * agroup: is key to specify audio group. A string can be given as value.
>      */
>     p = av_strdup(hls->var_stream_map);
>     q = p;
> @@ -1554,7 +1605,10 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
>         while (keyval = av_strtok(varstr, ",", &saveptr2)) {
>             varstr = NULL;
> 
> -            if (av_strstart(keyval, "v:", &val)) {
> +            if (av_strstart(keyval, "agroup:", &val)) {
> +                vs->agroup = av_strdup(val);
> +                continue;
> +            } else if (av_strstart(keyval, "v:", &val)) {
>                 codec_type = AVMEDIA_TYPE_VIDEO;
>             } else if (av_strstart(keyval, "a:", &val)) {
>                 codec_type = AVMEDIA_TYPE_AUDIO;
> @@ -1915,6 +1969,7 @@ static int hls_write_trailer(struct AVFormatContext *s)
>     av_free(old_filename);
>     av_freep(&vs->m3u8_name);
>     av_freep(&vs->streams);
> +    av_freep(&vs->agroup);
>     av_freep(&vs->baseurl);
>     }
> 
> @@ -2255,6 +2310,7 @@ fail:
>             av_freep(&vs->m3u8_name);
>             av_freep(&vs->vtt_m3u8_name);
>             av_freep(&vs->streams);
> +            av_freep(&vs->agroup);
>             av_freep(&vs->baseurl);
>             if (vs->avf)
>                 avformat_free_context(vs->avf);
> diff --git a/libavformat/hlsplaylist.c b/libavformat/hlsplaylist.c
> index 3349eb7..42f059a 100644
> --- a/libavformat/hlsplaylist.c
> +++ b/libavformat/hlsplaylist.c
> @@ -36,7 +36,7 @@ void ff_hls_write_playlist_version(AVIOContext *out, int version) {
> }
> 
> void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
> -                              int bandwidth, char *filename) {
> +                              int bandwidth, char *filename, char *agroup) {
>     if (!out || !filename)
>         return;
> 
> @@ -50,6 +50,8 @@ void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
>     if (st && st->codecpar->width > 0 && st->codecpar->height > 0)
>         avio_printf(out, ",RESOLUTION=%dx%d", st->codecpar->width,
>                 st->codecpar->height);
> +    if (agroup && strlen(agroup) > 0)
> +        avio_printf(out, ",AUDIO=\"group_%s\"", agroup);
>     avio_printf(out, "\n%s\n\n", filename);
> }
> 
> diff --git a/libavformat/hlsplaylist.h b/libavformat/hlsplaylist.h
> index 48d71b7..a3ce26c 100644
> --- a/libavformat/hlsplaylist.h
> +++ b/libavformat/hlsplaylist.h
> @@ -43,7 +43,7 @@ static inline int hls_get_int_from_double(double val)
> 
> void ff_hls_write_playlist_version(AVIOContext *out, int version);
> void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
> -                              int bandwidth, char *filename);
> +                              int bandwidth, char *filename, char *agroup);
> void ff_hls_write_playlist_header(AVIOContext *out, int version, int allowcache,
>                                   int target_duration, int64_t sequence,
>                                   uint32_t playlist_type);
> -- 
> 1.9.1
> 
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LGTM


Thanks

Steven




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