[FFmpeg-devel] libavformat/dashdec: Avoid multiple HTTP requests for initialization segment that is common among all representations

Submitted by sanilraut on April 9, 2018, 7:02 a.m.

Details

Message ID 1523257356-19294-1-git-send-email-raut.sanil@gmail.com
State New
Headers show

Commit Message

sanilraut April 9, 2018, 7:02 a.m.
Hi,

The following patch avoid multiple HTTP requests for initialization segment that is common among all representations.

---
 libavformat/dashdec.c | 96 ++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 83 insertions(+), 13 deletions(-)

Comments

Steven Liu April 9, 2018, 9:52 a.m.
> On 9 Apr 2018, at 15:02, sanilraut <raut.sanil@gmail.com> wrote:
> 
> Hi,
> 
> The following patch avoid multiple HTTP requests for initialization segment that is common among all representations.
> 
> ---
> libavformat/dashdec.c | 96 ++++++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 83 insertions(+), 13 deletions(-)
> 
> diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
> index 8bfde4d..4d0445f 100644
> --- a/libavformat/dashdec.c
> +++ b/libavformat/dashdec.c
> @@ -149,6 +149,11 @@ typedef struct DASHContext {
>     char *allowed_extensions;
>     AVDictionary *avio_opts;
>     int max_url_size;
> +
> +    /* Flags for init section*/
> +    int is_init_section_common_video;
> +    int is_init_section_common_audio;
> +
> } DASHContext;
> 
> static int ishttp(char *url)
> @@ -416,9 +421,9 @@ static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
>     if (av_strstart(proto_name, "file", NULL)) {
>         if (strcmp(c->allowed_extensions, "ALL") && !av_match_ext(url, c->allowed_extensions)) {
>             av_log(s, AV_LOG_ERROR,
> -                "Filename extension of \'%s\' is not a common multimedia extension, blocked for security reasons.\n"
> -                "If you wish to override this adjust allowed_extensions, you can set it to \'ALL\' to allow all\n",
> -                url);
> +                   "Filename extension of \'%s\' is not a common multimedia extension, blocked for security reasons.\n"
> +                   "If you wish to override this adjust allowed_extensions, you can set it to \'ALL\' to allow all\n",
> +                   url);
>             return AVERROR_INVALIDDATA;
>         }
>     } else if (av_strstart(proto_name, "http", NULL)) {
> @@ -931,7 +936,7 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url,
>                         rep->last_seq_no =(int64_t) strtoll(val, NULL, 10) - 1;
>                         xmlFree(val);
>                     }
> -                 }
> +                }
>             }
> 
>             fragment_timeline_node = find_child_node_by_name(representation_segmenttemplate_node, "SegmentTimeline");
> @@ -1160,7 +1165,7 @@ static int parse_manifest(AVFormatContext *s, const char *url, AVIOContext *in)
>     } else {
>         LIBXML_TEST_VERSION
> 
> -        doc = xmlReadMemory(buffer, filesize, c->base_url, NULL, 0);
> +            doc = xmlReadMemory(buffer, filesize, c->base_url, NULL, 0);
>         root_element = xmlDocGetRootElement(doc);
>         node = root_element;
> 
> @@ -1396,14 +1401,14 @@ static int refresh_manifest(AVFormatContext *s)
> 
>     if (c->n_videos != n_videos) {
>         av_log(c, AV_LOG_ERROR,
> -            "new manifest has mismatched no. of video representations, %d -> %d\n",
> -            n_videos, c->n_videos);
> +               "new manifest has mismatched no. of video representations, %d -> %d\n",
> +               n_videos, c->n_videos);
>         return AVERROR_INVALIDDATA;
>     }
>     if (c->n_audios != n_audios) {
>         av_log(c, AV_LOG_ERROR,
> -            "new manifest has mismatched no. of audio representations, %d -> %d\n",
> -            n_audios, c->n_audios);
> +               "new manifest has mismatched no. of audio representations, %d -> %d\n",
> +               n_audios, c->n_audios);
>         return AVERROR_INVALIDDATA;
>     }
> 
> @@ -1862,6 +1867,45 @@ fail:
>     return ret;
> }
> 
> +static int init_section_compare_video(DASHContext *c)
> +{
> +    int i = 0;
> +    char *url = c->videos[0]->init_section->url;
> +    int64_t url_offset = c->videos[0]->init_section->url_offset;
> +    int64_t size = c->videos[0]->init_section->size;
> +    for (i=0;i<c->n_videos;i++) {
> +        if (av_strcasecmp(c->videos[i]->init_section->url,url) || c->videos[i]->init_section->url_offset != url_offset || c->videos[i]->init_section->size != size) {
> +            return 0;
> +        }
> +    }
> +    return 1;
> +}
> +
> +static int init_section_compare_audio(DASHContext *c)
> +{
> +    int i = 0;
> +    char *url = c->audios[0]->init_section->url;
> +    int64_t url_offset = c->audios[0]->init_section->url_offset;
> +    int64_t size = c->audios[0]->init_section->size;
> +    for (i=0;i<c->n_audios;i++) {
> +        if (av_strcasecmp(c->audios[i]->init_section->url,url) || c->audios[i]->init_section->url_offset != url_offset || c->audios[i]->init_section->size != size) {
> +            return 0;
> +        }
> +    }
> +    return 1;
> +}
> +
> +static void copy_init_section(struct representation *rep_dest, struct representation *rep_src)
> +{
> +    memcpy(rep_dest->init_section, rep_src->init_section, sizeof(rep_src->init_section));
> +    rep_dest->init_sec_buf = av_mallocz(rep_src->init_sec_buf_size);
> +    memcpy(rep_dest->init_sec_buf, rep_src->init_sec_buf, rep_src->init_sec_data_len);
> +    rep_dest->init_sec_buf_size = rep_src->init_sec_buf_size;
> +    rep_dest->init_sec_data_len = rep_src->init_sec_data_len;
> +    rep_dest->cur_timestamp = rep_src->cur_timestamp;
> +}
> +
> +
> static int dash_read_header(AVFormatContext *s)
> {
>     void *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb;
> @@ -1890,19 +1934,45 @@ static int dash_read_header(AVFormatContext *s)
>         s->duration = (int64_t) c->media_presentation_duration * AV_TIME_BASE;
>     }
> 
> +    if (c->n_videos != 0) {
if(c->n_videos)
> +        c->is_init_section_common_video = init_section_compare_video(c);
> +    }
> +
>     /* Open the demuxer for video and audio components if available */
>     for (i = 0; i < c->n_videos; i++) {
>         struct representation *cur_video = c->videos[i];
> -        ret = open_demux_for_component(s, cur_video);
> +        if (!c->is_init_section_common_video) {
> +            ret = open_demux_for_component(s, cur_video);
> +        } else {
> +            if (i == 0) {
> +                ret = open_demux_for_component(s, cur_video);
> +            } else {
> +                copy_init_section(cur_video,c->videos[0]);
> +                ret = open_demux_for_component(s, cur_video);
> +            }
if (i > 0 && c->is_init_section_common_video) {
    copy_init_section(cur_video,c->videos[0]);
}
ret = open_demux_for_component(s, cur_video);

Is this same as the logic of your code?

> +        }
>         if (ret)
>             goto fail;
>         cur_video->stream_index = stream_index;
>         ++stream_index;
>     }
> 
> +    if (c->n_audios != 0) {
same as above
> +        c->is_init_section_common_audio = init_section_compare_audio(c);
> +    }
> +
>     for (i = 0; i < c->n_audios; i++) {
>         struct representation *cur_audio = c->audios[i];
> -        ret = open_demux_for_component(s, cur_audio);
> +        if (!c->is_init_section_common_audio) {
> +            ret = open_demux_for_component(s, cur_audio);
> +        } else {
> +            if (i == 0) {
> +                ret = open_demux_for_component(s, cur_audio);
> +            } else {
> +                copy_init_section(cur_audio,c->audios[0]);
> +                ret = open_demux_for_component(s, cur_audio);
> +            }
> +        }
same as above
>         if (ret)
>             goto fail;
>         cur_audio->stream_index = stream_index;
> @@ -1931,7 +2001,7 @@ static int dash_read_header(AVFormatContext *s)
>                 av_dict_set_int(&pls->assoc_stream->metadata, "variant_bitrate", pls->bandwidth, 0);
>             if (pls->id[0])
>                 av_dict_set(&pls->assoc_stream->metadata, "id", pls->id, 0);
> -         }
> +        }
>         for (i = 0; i < c->n_audios; i++) {
>             struct representation *pls = c->audios[i];
> 
> @@ -2048,7 +2118,7 @@ static int dash_seek(AVFormatContext *s, struct representation *pls, int64_t see
>     int64_t duration = 0;
> 
>     av_log(pls->parent, AV_LOG_VERBOSE, "DASH seek pos[%"PRId64"ms], playlist %d%s\n",
> -            seek_pos_msec, pls->rep_idx, dry_run ? " (dry)" : "");
> +           seek_pos_msec, pls->rep_idx, dry_run ? " (dry)" : "");
> 
>     // single fragment mode
>     if (pls->n_fragments == 1) {
> -- 
> 
> Thanks
> 
> 2.7.4
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

Thanks
Steven
sanilraut April 10, 2018, 7:04 a.m.
Hi Steven,

The changes mentioned have the same logic. I have re-submitted the patch.

Thanks,
Sanil

On Mon, Apr 9, 2018 at 2:52 AM, Steven Liu <lq@chinaffmpeg.org> wrote:

>
>
> > On 9 Apr 2018, at 15:02, sanilraut <raut.sanil@gmail.com> wrote:
> >
> > Hi,
> >
> > The following patch avoid multiple HTTP requests for initialization
> segment that is common among all representations.
> >
> > ---
> > libavformat/dashdec.c | 96 ++++++++++++++++++++++++++++++
> ++++++++++++++-------
> > 1 file changed, 83 insertions(+), 13 deletions(-)
> >
> > diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
> > index 8bfde4d..4d0445f 100644
> > --- a/libavformat/dashdec.c
> > +++ b/libavformat/dashdec.c
> > @@ -149,6 +149,11 @@ typedef struct DASHContext {
> >     char *allowed_extensions;
> >     AVDictionary *avio_opts;
> >     int max_url_size;
> > +
> > +    /* Flags for init section*/
> > +    int is_init_section_common_video;
> > +    int is_init_section_common_audio;
> > +
> > } DASHContext;
> >
> > static int ishttp(char *url)
> > @@ -416,9 +421,9 @@ static int open_url(AVFormatContext *s, AVIOContext
> **pb, const char *url,
> >     if (av_strstart(proto_name, "file", NULL)) {
> >         if (strcmp(c->allowed_extensions, "ALL") && !av_match_ext(url,
> c->allowed_extensions)) {
> >             av_log(s, AV_LOG_ERROR,
> > -                "Filename extension of \'%s\' is not a common
> multimedia extension, blocked for security reasons.\n"
> > -                "If you wish to override this adjust
> allowed_extensions, you can set it to \'ALL\' to allow all\n",
> > -                url);
> > +                   "Filename extension of \'%s\' is not a common
> multimedia extension, blocked for security reasons.\n"
> > +                   "If you wish to override this adjust
> allowed_extensions, you can set it to \'ALL\' to allow all\n",
> > +                   url);
> >             return AVERROR_INVALIDDATA;
> >         }
> >     } else if (av_strstart(proto_name, "http", NULL)) {
> > @@ -931,7 +936,7 @@ static int parse_manifest_representation(AVFormatContext
> *s, const char *url,
> >                         rep->last_seq_no =(int64_t) strtoll(val, NULL,
> 10) - 1;
> >                         xmlFree(val);
> >                     }
> > -                 }
> > +                }
> >             }
> >
> >             fragment_timeline_node = find_child_node_by_name(
> representation_segmenttemplate_node, "SegmentTimeline");
> > @@ -1160,7 +1165,7 @@ static int parse_manifest(AVFormatContext *s,
> const char *url, AVIOContext *in)
> >     } else {
> >         LIBXML_TEST_VERSION
> >
> > -        doc = xmlReadMemory(buffer, filesize, c->base_url, NULL, 0);
> > +            doc = xmlReadMemory(buffer, filesize, c->base_url, NULL, 0);
> >         root_element = xmlDocGetRootElement(doc);
> >         node = root_element;
> >
> > @@ -1396,14 +1401,14 @@ static int refresh_manifest(AVFormatContext *s)
> >
> >     if (c->n_videos != n_videos) {
> >         av_log(c, AV_LOG_ERROR,
> > -            "new manifest has mismatched no. of video representations,
> %d -> %d\n",
> > -            n_videos, c->n_videos);
> > +               "new manifest has mismatched no. of video
> representations, %d -> %d\n",
> > +               n_videos, c->n_videos);
> >         return AVERROR_INVALIDDATA;
> >     }
> >     if (c->n_audios != n_audios) {
> >         av_log(c, AV_LOG_ERROR,
> > -            "new manifest has mismatched no. of audio representations,
> %d -> %d\n",
> > -            n_audios, c->n_audios);
> > +               "new manifest has mismatched no. of audio
> representations, %d -> %d\n",
> > +               n_audios, c->n_audios);
> >         return AVERROR_INVALIDDATA;
> >     }
> >
> > @@ -1862,6 +1867,45 @@ fail:
> >     return ret;
> > }
> >
> > +static int init_section_compare_video(DASHContext *c)
> > +{
> > +    int i = 0;
> > +    char *url = c->videos[0]->init_section->url;
> > +    int64_t url_offset = c->videos[0]->init_section->url_offset;
> > +    int64_t size = c->videos[0]->init_section->size;
> > +    for (i=0;i<c->n_videos;i++) {
> > +        if (av_strcasecmp(c->videos[i]->init_section->url,url) ||
> c->videos[i]->init_section->url_offset != url_offset ||
> c->videos[i]->init_section->size != size) {
> > +            return 0;
> > +        }
> > +    }
> > +    return 1;
> > +}
> > +
> > +static int init_section_compare_audio(DASHContext *c)
> > +{
> > +    int i = 0;
> > +    char *url = c->audios[0]->init_section->url;
> > +    int64_t url_offset = c->audios[0]->init_section->url_offset;
> > +    int64_t size = c->audios[0]->init_section->size;
> > +    for (i=0;i<c->n_audios;i++) {
> > +        if (av_strcasecmp(c->audios[i]->init_section->url,url) ||
> c->audios[i]->init_section->url_offset != url_offset ||
> c->audios[i]->init_section->size != size) {
> > +            return 0;
> > +        }
> > +    }
> > +    return 1;
> > +}
> > +
> > +static void copy_init_section(struct representation *rep_dest, struct
> representation *rep_src)
> > +{
> > +    memcpy(rep_dest->init_section, rep_src->init_section,
> sizeof(rep_src->init_section));
> > +    rep_dest->init_sec_buf = av_mallocz(rep_src->init_sec_buf_size);
> > +    memcpy(rep_dest->init_sec_buf, rep_src->init_sec_buf,
> rep_src->init_sec_data_len);
> > +    rep_dest->init_sec_buf_size = rep_src->init_sec_buf_size;
> > +    rep_dest->init_sec_data_len = rep_src->init_sec_data_len;
> > +    rep_dest->cur_timestamp = rep_src->cur_timestamp;
> > +}
> > +
> > +
> > static int dash_read_header(AVFormatContext *s)
> > {
> >     void *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb;
> > @@ -1890,19 +1934,45 @@ static int dash_read_header(AVFormatContext *s)
> >         s->duration = (int64_t) c->media_presentation_duration *
> AV_TIME_BASE;
> >     }
> >
> > +    if (c->n_videos != 0) {
> if(c->n_videos)
> > +        c->is_init_section_common_video =
> init_section_compare_video(c);
> > +    }
> > +
> >     /* Open the demuxer for video and audio components if available */
> >     for (i = 0; i < c->n_videos; i++) {
> >         struct representation *cur_video = c->videos[i];
> > -        ret = open_demux_for_component(s, cur_video);
> > +        if (!c->is_init_section_common_video) {
> > +            ret = open_demux_for_component(s, cur_video);
> > +        } else {
> > +            if (i == 0) {
> > +                ret = open_demux_for_component(s, cur_video);
> > +            } else {
> > +                copy_init_section(cur_video,c->videos[0]);
> > +                ret = open_demux_for_component(s, cur_video);
> > +            }
> if (i > 0 && c->is_init_section_common_video) {
>     copy_init_section(cur_video,c->videos[0]);
> }
> ret = open_demux_for_component(s, cur_video);
>
> Is this same as the logic of your code?
>
> > +        }
> >         if (ret)
> >             goto fail;
> >         cur_video->stream_index = stream_index;
> >         ++stream_index;
> >     }
> >
> > +    if (c->n_audios != 0) {
> same as above
> > +        c->is_init_section_common_audio =
> init_section_compare_audio(c);
> > +    }
> > +
> >     for (i = 0; i < c->n_audios; i++) {
> >         struct representation *cur_audio = c->audios[i];
> > -        ret = open_demux_for_component(s, cur_audio);
> > +        if (!c->is_init_section_common_audio) {
> > +            ret = open_demux_for_component(s, cur_audio);
> > +        } else {
> > +            if (i == 0) {
> > +                ret = open_demux_for_component(s, cur_audio);
> > +            } else {
> > +                copy_init_section(cur_audio,c->audios[0]);
> > +                ret = open_demux_for_component(s, cur_audio);
> > +            }
> > +        }
> same as above
> >         if (ret)
> >             goto fail;
> >         cur_audio->stream_index = stream_index;
> > @@ -1931,7 +2001,7 @@ static int dash_read_header(AVFormatContext *s)
> >                 av_dict_set_int(&pls->assoc_stream->metadata,
> "variant_bitrate", pls->bandwidth, 0);
> >             if (pls->id[0])
> >                 av_dict_set(&pls->assoc_stream->metadata, "id",
> pls->id, 0);
> > -         }
> > +        }
> >         for (i = 0; i < c->n_audios; i++) {
> >             struct representation *pls = c->audios[i];
> >
> > @@ -2048,7 +2118,7 @@ static int dash_seek(AVFormatContext *s, struct
> representation *pls, int64_t see
> >     int64_t duration = 0;
> >
> >     av_log(pls->parent, AV_LOG_VERBOSE, "DASH seek pos[%"PRId64"ms],
> playlist %d%s\n",
> > -            seek_pos_msec, pls->rep_idx, dry_run ? " (dry)" : "");
> > +           seek_pos_msec, pls->rep_idx, dry_run ? " (dry)" : "");
> >
> >     // single fragment mode
> >     if (pls->n_fragments == 1) {
> > --
> >
> > Thanks
> >
> > 2.7.4
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel@ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> Thanks
> Steven
>
>
>
>

Patch hide | download patch | download mbox

diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
index 8bfde4d..4d0445f 100644
--- a/libavformat/dashdec.c
+++ b/libavformat/dashdec.c
@@ -149,6 +149,11 @@  typedef struct DASHContext {
     char *allowed_extensions;
     AVDictionary *avio_opts;
     int max_url_size;
+
+    /* Flags for init section*/
+    int is_init_section_common_video;
+    int is_init_section_common_audio;
+
 } DASHContext;
 
 static int ishttp(char *url)
@@ -416,9 +421,9 @@  static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
     if (av_strstart(proto_name, "file", NULL)) {
         if (strcmp(c->allowed_extensions, "ALL") && !av_match_ext(url, c->allowed_extensions)) {
             av_log(s, AV_LOG_ERROR,
-                "Filename extension of \'%s\' is not a common multimedia extension, blocked for security reasons.\n"
-                "If you wish to override this adjust allowed_extensions, you can set it to \'ALL\' to allow all\n",
-                url);
+                   "Filename extension of \'%s\' is not a common multimedia extension, blocked for security reasons.\n"
+                   "If you wish to override this adjust allowed_extensions, you can set it to \'ALL\' to allow all\n",
+                   url);
             return AVERROR_INVALIDDATA;
         }
     } else if (av_strstart(proto_name, "http", NULL)) {
@@ -931,7 +936,7 @@  static int parse_manifest_representation(AVFormatContext *s, const char *url,
                         rep->last_seq_no =(int64_t) strtoll(val, NULL, 10) - 1;
                         xmlFree(val);
                     }
-                 }
+                }
             }
 
             fragment_timeline_node = find_child_node_by_name(representation_segmenttemplate_node, "SegmentTimeline");
@@ -1160,7 +1165,7 @@  static int parse_manifest(AVFormatContext *s, const char *url, AVIOContext *in)
     } else {
         LIBXML_TEST_VERSION
 
-        doc = xmlReadMemory(buffer, filesize, c->base_url, NULL, 0);
+            doc = xmlReadMemory(buffer, filesize, c->base_url, NULL, 0);
         root_element = xmlDocGetRootElement(doc);
         node = root_element;
 
@@ -1396,14 +1401,14 @@  static int refresh_manifest(AVFormatContext *s)
 
     if (c->n_videos != n_videos) {
         av_log(c, AV_LOG_ERROR,
-            "new manifest has mismatched no. of video representations, %d -> %d\n",
-            n_videos, c->n_videos);
+               "new manifest has mismatched no. of video representations, %d -> %d\n",
+               n_videos, c->n_videos);
         return AVERROR_INVALIDDATA;
     }
     if (c->n_audios != n_audios) {
         av_log(c, AV_LOG_ERROR,
-            "new manifest has mismatched no. of audio representations, %d -> %d\n",
-            n_audios, c->n_audios);
+               "new manifest has mismatched no. of audio representations, %d -> %d\n",
+               n_audios, c->n_audios);
         return AVERROR_INVALIDDATA;
     }
 
@@ -1862,6 +1867,45 @@  fail:
     return ret;
 }
 
+static int init_section_compare_video(DASHContext *c)
+{
+    int i = 0;
+    char *url = c->videos[0]->init_section->url;
+    int64_t url_offset = c->videos[0]->init_section->url_offset;
+    int64_t size = c->videos[0]->init_section->size;
+    for (i=0;i<c->n_videos;i++) {
+        if (av_strcasecmp(c->videos[i]->init_section->url,url) || c->videos[i]->init_section->url_offset != url_offset || c->videos[i]->init_section->size != size) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+static int init_section_compare_audio(DASHContext *c)
+{
+    int i = 0;
+    char *url = c->audios[0]->init_section->url;
+    int64_t url_offset = c->audios[0]->init_section->url_offset;
+    int64_t size = c->audios[0]->init_section->size;
+    for (i=0;i<c->n_audios;i++) {
+        if (av_strcasecmp(c->audios[i]->init_section->url,url) || c->audios[i]->init_section->url_offset != url_offset || c->audios[i]->init_section->size != size) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+static void copy_init_section(struct representation *rep_dest, struct representation *rep_src)
+{
+    memcpy(rep_dest->init_section, rep_src->init_section, sizeof(rep_src->init_section));
+    rep_dest->init_sec_buf = av_mallocz(rep_src->init_sec_buf_size);
+    memcpy(rep_dest->init_sec_buf, rep_src->init_sec_buf, rep_src->init_sec_data_len);
+    rep_dest->init_sec_buf_size = rep_src->init_sec_buf_size;
+    rep_dest->init_sec_data_len = rep_src->init_sec_data_len;
+    rep_dest->cur_timestamp = rep_src->cur_timestamp;
+}
+
+
 static int dash_read_header(AVFormatContext *s)
 {
     void *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb;
@@ -1890,19 +1934,45 @@  static int dash_read_header(AVFormatContext *s)
         s->duration = (int64_t) c->media_presentation_duration * AV_TIME_BASE;
     }
 
+    if (c->n_videos != 0) {
+        c->is_init_section_common_video = init_section_compare_video(c);
+    }
+
     /* Open the demuxer for video and audio components if available */
     for (i = 0; i < c->n_videos; i++) {
         struct representation *cur_video = c->videos[i];
-        ret = open_demux_for_component(s, cur_video);
+        if (!c->is_init_section_common_video) {
+            ret = open_demux_for_component(s, cur_video);
+        } else {
+            if (i == 0) {
+                ret = open_demux_for_component(s, cur_video);
+            } else {
+                copy_init_section(cur_video,c->videos[0]);
+                ret = open_demux_for_component(s, cur_video);
+            }
+        }
         if (ret)
             goto fail;
         cur_video->stream_index = stream_index;
         ++stream_index;
     }
 
+    if (c->n_audios != 0) {
+        c->is_init_section_common_audio = init_section_compare_audio(c);
+    }
+
     for (i = 0; i < c->n_audios; i++) {
         struct representation *cur_audio = c->audios[i];
-        ret = open_demux_for_component(s, cur_audio);
+        if (!c->is_init_section_common_audio) {
+            ret = open_demux_for_component(s, cur_audio);
+        } else {
+            if (i == 0) {
+                ret = open_demux_for_component(s, cur_audio);
+            } else {
+                copy_init_section(cur_audio,c->audios[0]);
+                ret = open_demux_for_component(s, cur_audio);
+            }
+        }
         if (ret)
             goto fail;
         cur_audio->stream_index = stream_index;
@@ -1931,7 +2001,7 @@  static int dash_read_header(AVFormatContext *s)
                 av_dict_set_int(&pls->assoc_stream->metadata, "variant_bitrate", pls->bandwidth, 0);
             if (pls->id[0])
                 av_dict_set(&pls->assoc_stream->metadata, "id", pls->id, 0);
-         }
+        }
         for (i = 0; i < c->n_audios; i++) {
             struct representation *pls = c->audios[i];
 
@@ -2048,7 +2118,7 @@  static int dash_seek(AVFormatContext *s, struct representation *pls, int64_t see
     int64_t duration = 0;
 
     av_log(pls->parent, AV_LOG_VERBOSE, "DASH seek pos[%"PRId64"ms], playlist %d%s\n",
-            seek_pos_msec, pls->rep_idx, dry_run ? " (dry)" : "");
+           seek_pos_msec, pls->rep_idx, dry_run ? " (dry)" : "");
 
     // single fragment mode
     if (pls->n_fragments == 1) {