[FFmpeg-devel] [PATCH v2] libavformat/dashdec: Avoid multiple HTTP requests for initialization segment that is common among all representations
Steven Liu
lq at chinaffmpeg.org
Tue Apr 17 09:21:30 EEST 2018
> On 10 Apr 2018, at 15:02, sanilraut <raut.sanil at gmail.com> wrote:
>
> Hi,
>
> The following patch avoid multiple HTTP requests for initialization segment that is common among all representations.
>
> ---
> libavformat/dashdec.c | 82 ++++++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 71 insertions(+), 11 deletions(-)
>
> diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
> index 8bfde4d..6304ad9 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 +1934,35 @@ static int dash_read_header(AVFormatContext *s)
> s->duration = (int64_t) c->media_presentation_duration * AV_TIME_BASE;
> }
>
> + 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];
> + 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);
> +
> if (ret)
> goto fail;
> cur_video->stream_index = stream_index;
> ++stream_index;
> }
>
> + if (c->n_audios) {
> + 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];
> + if (i > 0 && c->is_init_section_common_audio) {
> + 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 +1991,7 @@ 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 +2108,7 @@ 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
>
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Pushed
Thanks
Steven
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