[FFmpeg-devel] [PATCH v7 1/3] avformat/hlsenc:addition of #EXT-X-MEDIA tag and AUDIO attribute
刘歧
lq at chinaffmpeg.org
Tue Dec 19 05:53:45 EET 2017
> On 18 Dec 2017, at 20:52, vdixit at akamai.com wrote:
>
> 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 e3442c3..2903e4e 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;
>
> @@ -1085,7 +1086,7 @@ 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;
> AVDictionary *options = NULL;
> unsigned int i, j;
> @@ -1117,6 +1118,34 @@ static int create_master_playlist(AVFormatContext *s,
>
> ff_hls_write_playlist_version(hls->m3u8_out, 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(hls->m3u8_out, "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"group_%s\"",
> + vs->agroup);
> + avio_printf(hls->m3u8_out, ",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]);
> @@ -1149,6 +1178,25 @@ 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)) {
Why don’t use av_strcasecmp,
> + 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;
> @@ -1156,7 +1204,8 @@ static int create_master_playlist(AVFormatContext *s,
> bandwidth += aud_st->codecpar->bit_rate;
> bandwidth += bandwidth / 10;
>
> - ff_hls_write_stream_info(vid_st, hls->m3u8_out, bandwidth, m3u8_rel_name);
> + ff_hls_write_stream_info(vid_st, hls->m3u8_out, 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);
What will happen when av_strdup failed?
> + 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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