Each subtile segment is a WebVTT file and needs to be demuxed separately. These segments also contain a header to synchronize their timing with the MPEG TS stream so those timestamps are requested from the WebVTT demuxer through an AVOption.
Signed-off-by: Franklin Phillips <franklinphill...@gmx.com> --- libavformat/hls.c | 196 ++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 138 insertions(+), 58 deletions(-) diff --git a/libavformat/hls.c b/libavformat/hls.c index 3ae3c7c..278c3b2 100644 --- a/libavformat/hls.c +++ b/libavformat/hls.c @@ -153,6 +153,8 @@ struct playlist { * playlist, if any. */ int n_init_sections; struct segment **init_sections; + + int is_subtitle; /* Indicates if it's a subtitle playlist */ }; /* @@ -203,6 +205,7 @@ typedef struct HLSContext { char *headers; ///< holds HTTP headers set as an AVOption to the HTTP protocol context char *http_proxy; ///< holds the address of the HTTP proxy server AVDictionary *avio_opts; + AVDictionary *demuxer_opts; int strict_std_compliance; } HLSContext; @@ -309,6 +312,8 @@ static struct playlist *new_playlist(HLSContext *c, const char *url, ff_make_absolute_url(pls->url, sizeof(pls->url), base, url); pls->seek_timestamp = AV_NOPTS_VALUE; + pls->is_subtitle = 0; + pls->is_id3_timestamped = -1; pls->id3_mpegts_timestamp = AV_NOPTS_VALUE; @@ -482,11 +487,6 @@ static struct rendition *new_rendition(HLSContext *c, struct rendition_info *inf if (type == AVMEDIA_TYPE_SUBTITLE && !info->uri[0]) return NULL; - /* TODO: handle subtitles (each segment has to parsed separately) */ - if (c->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) - if (type == AVMEDIA_TYPE_SUBTITLE) - return NULL; - rend = av_mallocz(sizeof(struct rendition)); if (!rend) return NULL; @@ -501,9 +501,14 @@ static struct rendition *new_rendition(HLSContext *c, struct rendition_info *inf /* add the playlist if this is an external rendition */ if (info->uri[0]) { rend->playlist = new_playlist(c, info->uri, url_base); - if (rend->playlist) + if (rend->playlist) { dynarray_add(&rend->playlist->renditions, &rend->playlist->n_renditions, rend); + if (type == AVMEDIA_TYPE_SUBTITLE) { + rend->playlist->is_subtitle = 1; + rend->playlist->is_id3_timestamped = 0; + } + } } if (info->assoc_language[0]) { @@ -1241,8 +1246,103 @@ static int read_data(void *opaque, uint8_t *buf, int buf_size) { struct playlist *v = opaque; HLSContext *c = v->parent->priv_data; - int ret, i; - int just_opened = 0; + int ret, just_opened = 0; + struct segment *seg; + + if (v->cur_seq_no - v->start_seq_no >= v->n_segments) { + return AVERROR_EOF; + } else { + seg = current_segment(v); + } + + if (!v->input) { + /* load/update Media Initialization Section, if any */ + ret = update_init_section(v, seg); + if (ret < 0) + return ret; + + ret = open_input(c, v, seg); + if (ret < 0) { + if (ff_check_interrupt(c->interrupt_callback)) + return AVERROR_EXIT; + av_log(v->parent, AV_LOG_WARNING, "Failed to open segment of playlist %d\n", + v->index); + return ret; + } + just_opened = 1; + } + + if (v->init_sec_buf_read_offset < v->init_sec_data_len) { + /* Push init section out first before first actual segment */ + int copy_size = FFMIN(v->init_sec_data_len - v->init_sec_buf_read_offset, buf_size); + memcpy(buf, v->init_sec_buf, copy_size); + v->init_sec_buf_read_offset += copy_size; + return copy_size; + } + + ret = read_from_url(v, seg, buf, buf_size, READ_NORMAL); + if (ret > 0) { + if (just_opened && v->is_id3_timestamped != 0) { + /* Intercept ID3 tags here, elementary audio streams are required + * to convey timestamps using them in the beginning of each segment. */ + intercept_id3(v, buf, buf_size, &ret); + } + } + + return ret; +} + +static int nested_io_open(AVFormatContext *s, AVIOContext **pb, const char *url, + int flags, AVDictionary **opts) +{ + av_log(s, AV_LOG_ERROR, + "A HLS playlist item '%s' referred to an external file '%s'. " + "Opening this file was forbidden for security reasons\n", + s->filename, url); + return AVERROR(EPERM); +} + +static int init_subtitle_context(struct playlist *pls) +{ + HLSContext *c = pls->parent->priv_data; + AVInputFormat *in_fmt; + AVDictionary *opts = NULL; + int ret = 0; + + if (!(pls->ctx = avformat_alloc_context())) + return AVERROR(ENOMEM); + + pls->read_buffer = av_malloc(INITIAL_BUFFER_SIZE); + if (!pls->read_buffer) { + avformat_free_context(pls->ctx); + pls->ctx = NULL; + return AVERROR(ENOMEM); + } + + ffio_init_context(&pls->pb, pls->read_buffer, INITIAL_BUFFER_SIZE, 0, pls, + read_data, NULL, NULL); + pls->pb.seekable = 0; + pls->ctx->pb = &pls->pb; + pls->ctx->io_open = nested_io_open; + + ret = ff_copy_whiteblacklists(pls->ctx, pls->parent); + if (ret < 0) + return ret; + + in_fmt = av_find_input_format("webvtt"); + av_dict_copy(&opts, c->demuxer_opts, 0); + ret = avformat_open_input(&pls->ctx, current_segment(pls)->url, in_fmt, &opts); + av_dict_free(&opts); + if (ret < 0) + return ret; + + return ret; +} + +static int read_packet(struct playlist *v, AVPacket *pkt) +{ + HLSContext *c = v->parent->priv_data; + int ret; restart: if (!v->needed) @@ -1250,11 +1350,11 @@ restart: if (!v->input) { int64_t reload_interval; - struct segment *seg; /* Check that the playlist is still needed before opening a new * segment. */ - if (v->ctx && v->ctx->nb_streams) { + if ((v->ctx && v->ctx->nb_streams) || v->is_subtitle) { + int i; v->needed = 0; for (i = 0; i < v->n_main_streams; i++) { if (v->main_streams[i]->discard < AVDISCARD_ALL) { @@ -1270,7 +1370,7 @@ restart: } /* If this is a live stream and the reload interval has elapsed since - * the last playlist reload, reload the playlists now. */ + * the last playlist reload, reload the playlists now. */ reload_interval = default_reload_interval(v); reload: @@ -1293,7 +1393,7 @@ reload: v->cur_seq_no = v->start_seq_no; } if (v->cur_seq_no >= v->start_seq_no + v->n_segments) { - if (v->finished) + if (v->finished || v->is_subtitle) return AVERROR_EOF; while (av_gettime_relative() - v->last_load_time < reload_interval) { if (ff_check_interrupt(c->interrupt_callback)) @@ -1304,48 +1404,26 @@ reload: goto reload; } - seg = current_segment(v); - - /* load/update Media Initialization Section, if any */ - ret = update_init_section(v, seg); - if (ret) - return ret; - - ret = open_input(c, v, seg); - if (ret < 0) { - if (ff_check_interrupt(c->interrupt_callback)) - return AVERROR_EXIT; - av_log(v->parent, AV_LOG_WARNING, "Failed to open segment of playlist %d\n", - v->index); - v->cur_seq_no += 1; - goto reload; + if (!v->ctx && v->is_subtitle) { + ret = init_subtitle_context(v); + if (ret < 0) + return ret; } - just_opened = 1; } - if (v->init_sec_buf_read_offset < v->init_sec_data_len) { - /* Push init section out first before first actual segment */ - int copy_size = FFMIN(v->init_sec_data_len - v->init_sec_buf_read_offset, buf_size); - memcpy(buf, v->init_sec_buf, copy_size); - v->init_sec_buf_read_offset += copy_size; - return copy_size; - } - - ret = read_from_url(v, current_segment(v), buf, buf_size, READ_NORMAL); - if (ret > 0) { - if (just_opened && v->is_id3_timestamped != 0) { - /* Intercept ID3 tags here, elementary audio streams are required - * to convey timestamps using them in the beginning of each segment. */ - intercept_id3(v, buf, buf_size, &ret); - } - + /* EOF flag may get set when the end of a segment is reached */ + v->pb.eof_reached = 0; + ret = av_read_frame(v->ctx, &v->pkt); + if (!ret) { return ret; } ff_format_io_close(v->parent, &v->input); v->cur_seq_no++; - c->cur_seq_no = v->cur_seq_no; + if (v->is_subtitle) + avformat_close_input(&v->ctx); + goto restart; } @@ -1492,16 +1570,6 @@ static int save_avio_options(AVFormatContext *s) return ret; } -static int nested_io_open(AVFormatContext *s, AVIOContext **pb, const char *url, - int flags, AVDictionary **opts) -{ - av_log(s, AV_LOG_ERROR, - "A HLS playlist item '%s' referred to an external file '%s'. " - "Opening this file was forbidden for security reasons\n", - s->filename, url); - return AVERROR(EPERM); -} - static void add_stream_to_programs(AVFormatContext *s, struct playlist *pls, AVStream *stream) { HLSContext *c = s->priv_data; @@ -1602,6 +1670,7 @@ static int hls_close(AVFormatContext *s) free_rendition_list(c); av_dict_free(&c->avio_opts); + av_dict_free(&c->demuxer_opts); return 0; } @@ -1708,10 +1777,13 @@ static int hls_read_header(AVFormatContext *s) highest_cur_seq_no = FFMAX(highest_cur_seq_no, pls->cur_seq_no); } + av_dict_set(&c->demuxer_opts, "prefer_hls_mpegts_pts", "1", 0); + /* Open the demuxer for each playlist */ for (i = 0; i < c->n_playlists; i++) { struct playlist *pls = c->playlists[i]; AVInputFormat *in_fmt = NULL; + AVDictionary *opts = NULL; if (!(pls->ctx = avformat_alloc_context())) { ret = AVERROR(ENOMEM); @@ -1765,7 +1837,9 @@ static int hls_read_header(AVFormatContext *s) if ((ret = ff_copy_whiteblacklists(pls->ctx, s)) < 0) goto fail; - ret = avformat_open_input(&pls->ctx, pls->segments[0]->url, in_fmt, NULL); + av_dict_copy(&opts, c->demuxer_opts, 0); + ret = avformat_open_input(&pls->ctx, pls->segments[0]->url, in_fmt, &opts); + av_dict_free(&opts); if (ret < 0) goto fail; @@ -1843,6 +1917,8 @@ static int recheck_discard_flags(AVFormatContext *s, int first) } else if (first && !pls->cur_needed && pls->needed) { if (pls->input) ff_format_io_close(pls->parent, &pls->input); + if (pls->is_subtitle) + avformat_close_input(&pls->ctx); pls->needed = 0; changed = 1; av_log(s, AV_LOG_INFO, "No longer receiving playlist %d\n", i); @@ -1909,7 +1985,7 @@ static int hls_read_packet(AVFormatContext *s, AVPacket *pkt) while (1) { int64_t ts_diff; AVRational tb; - ret = av_read_frame(pls->ctx, &pls->pkt); + ret = read_packet(pls, &pls->pkt); if (ret < 0) { if (!avio_feof(&pls->pb) && ret != AVERROR_EOF) return ret; @@ -2085,7 +2161,11 @@ static int hls_read_seek(AVFormatContext *s, int stream_index, /* Reset the pos, to let the mpegts demuxer know we've seeked. */ pls->pb.pos = 0; /* Flush the packet queue of the subdemuxer. */ - ff_read_frame_flush(pls->ctx); + if (pls->ctx) + ff_read_frame_flush(pls->ctx); + + if (pls->is_subtitle) + avformat_close_input(&pls->ctx); pls->seek_timestamp = seek_timestamp; pls->seek_flags = flags; -- 2.1.4 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel