[FFmpeg-devel] [PATCH v8 1/3] avformat/hlsenc:addition of #EXT-X-MEDIA tag and AUDIO attribute

刘歧 lq at chinaffmpeg.org
Fri Dec 22 13:30:31 EET 2017



> On 22 Dec 2017, at 19:05, Dixit, Vishwanath <vdixit at akamai.com> wrote:
> 
> 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.

That’s ok,

LGTM


Thanks

Steven
>>> +                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
>>> 
>>> _______________________________________________
>>> ffmpeg-devel mailing list
>>> ffmpeg-devel at ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> 
>> 
> 
> 
> 
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