[FFmpeg-devel] [PATCH v8 1/3] avformat/hlsenc:addition of #EXT-X-MEDIA tag and AUDIO attribute
Dixit, Vishwanath
vdixit at akamai.com
Fri Dec 22 13:05:50 EET 2017
On 12/19/17 11:53 AM, 刘歧 wrote:
> On 19 Dec 2017, at 14:09, vdixit at akamai.com wrote:
>> From: Vishwanath Dixit <vdixit at akamai.com>
>>
>> ---
>> doc/muxers.texi | 12 +++++++++
>> libavformat/dashenc.c | 3 ++-
>> libavformat/hlsenc.c | 64 ++++++++++++++++++++++++++++++++++++++++++++---
>> libavformat/hlsplaylist.c | 4 ++-
>> libavformat/hlsplaylist.h | 2 +-
>> 5 files changed, 79 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..53dc835 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 &&
>> + !av_strcasecmp(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;
>> @@ -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 +1605,12 @@ 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);
>> + if (!vs->agroup)
>> + return AVERROR(ENOMEM);
> I’m not sure if return here, dose the p = av_strdup will not av_free and memleak, maybe use goto or free the memory which be alloced before?
The memory that was allocated by p = av_strdup was already freed by av_freep(&p). Also, any other memory that was allocated before this return statement will eventually get freed by hls_init function's failure handling block in case of any errors. The function parse_variant_stream_mapstring is called by update_variant_stream_info which in turn is called by hls_init. So, the error gets propagated until failure handling block of hls_init where all the allocated memory gets freed up.
>> + 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 +1971,7 @@ 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 +2312,7 @@ 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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>
>
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