diff options
Diffstat (limited to 'libavformat/webmdashenc.c')
| -rw-r--r-- | libavformat/webmdashenc.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/libavformat/webmdashenc.c b/libavformat/webmdashenc.c new file mode 100644 index 0000000000..381efb7888 --- /dev/null +++ b/libavformat/webmdashenc.c @@ -0,0 +1,317 @@ +/* + * WebM DASH Manifest XML muxer + * Copyright (c) 2014 Vignesh Venkatasubramanian + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/* + * WebM DASH Specification: + * https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification + */ + +#include <stdint.h> +#include <string.h> + +#include "avformat.h" +#include "avio_internal.h" +#include "matroska.h" + +#include "libavutil/avstring.h" +#include "libavutil/dict.h" +#include "libavutil/opt.h" + +typedef struct AdaptationSet { + char id[10]; + int *streams; + int nb_streams; +} AdaptationSet; + +typedef struct WebMDashMuxContext { + const AVClass *class; + char *adaptation_sets; + AdaptationSet *as; + int nb_as; +} WebMDashMuxContext; + +static const char *get_codec_name(int codec_id) +{ + switch (codec_id) { + case AV_CODEC_ID_VP8: + return "vp8"; + case AV_CODEC_ID_VP9: + return "vp9"; + case AV_CODEC_ID_VORBIS: + return "vorbis"; + case AV_CODEC_ID_OPUS: + return "opus"; + } + return NULL; +} + +static double get_duration(AVFormatContext *s) +{ + int i = 0; + double max = 0.0; + for (i = 0; i < s->nb_streams; i++) { + AVDictionaryEntry *duration = av_dict_get(s->streams[i]->metadata, + DURATION, NULL, 0); + if (duration == NULL || atof(duration->value) < 0) continue; + if (atof(duration->value) > max) max = atof(duration->value); + } + return max / 1000; +} + +static void write_header(AVFormatContext *s) +{ + double min_buffer_time = 1.0; + avio_printf(s->pb, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"); + avio_printf(s->pb, "<MPD\n"); + avio_printf(s->pb, " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n"); + avio_printf(s->pb, " xmlns=\"urn:mpeg:DASH:schema:MPD:2011\"\n"); + avio_printf(s->pb, " xsi:schemaLocation=\"urn:mpeg:DASH:schema:MPD:2011\"\n"); + avio_printf(s->pb, " type=\"static\"\n"); + avio_printf(s->pb, " mediaPresentationDuration=\"PT%gS\"\n", + get_duration(s)); + avio_printf(s->pb, " minBufferTime=\"PT%gS\"\n", + min_buffer_time); + avio_printf(s->pb, " profiles=\"urn:webm:dash:profile:webm-on-demand:2012\""); + avio_printf(s->pb, ">\n"); +} + +static void write_footer(AVFormatContext *s) +{ + avio_printf(s->pb, "</MPD>"); +} + +static int subsegment_alignment(AVFormatContext *s, AdaptationSet *as) { + int i; + AVDictionaryEntry *gold = av_dict_get(s->streams[as->streams[0]]->metadata, + CUE_TIMESTAMPS, NULL, 0); + if (gold == NULL) return 0; + for (i = 1; i < as->nb_streams; i++) { + AVDictionaryEntry *ts = av_dict_get(s->streams[as->streams[i]]->metadata, + CUE_TIMESTAMPS, NULL, 0); + if (ts == NULL || strncmp(gold->value, ts->value, strlen(gold->value))) return 0; + } + return 1; +} + +static int bitstream_switching(AVFormatContext *s, AdaptationSet *as) { + int i; + AVDictionaryEntry *gold_track_num = av_dict_get(s->streams[as->streams[0]]->metadata, + TRACK_NUMBER, NULL, 0); + AVCodecContext *gold_codec = s->streams[as->streams[0]]->codec; + if (gold_track_num == NULL) return 0; + for (i = 1; i < as->nb_streams; i++) { + AVDictionaryEntry *track_num = av_dict_get(s->streams[as->streams[i]]->metadata, + TRACK_NUMBER, NULL, 0); + AVCodecContext *codec = s->streams[as->streams[i]]->codec; + if (track_num == NULL || + strncmp(gold_track_num->value, track_num->value, strlen(gold_track_num->value)) || + gold_codec->codec_id != codec->codec_id || + gold_codec->extradata_size != codec->extradata_size || + memcmp(gold_codec->extradata, codec->extradata, codec->extradata_size)) { + return 0; + } + } + return 1; +} + +/* + * Writes an Adaptation Set. Returns 0 on success and < 0 on failure. + */ +static int write_adaptation_set(AVFormatContext *s, int as_index) +{ + WebMDashMuxContext *w = s->priv_data; + AdaptationSet *as = &w->as[as_index]; + AVCodecContext *codec = s->streams[as->streams[0]]->codec; + int i; + static const char boolean[2][6] = { "false", "true" }; + int subsegmentStartsWithSAP = 1; + AVDictionaryEntry *lang; + avio_printf(s->pb, "<AdaptationSet id=\"%s\"", as->id); + avio_printf(s->pb, " mimeType=\"%s/webm\"", + codec->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio"); + avio_printf(s->pb, " codecs=\"%s\"", get_codec_name(codec->codec_id)); + + lang = av_dict_get(s->streams[as->streams[0]]->metadata, "language", NULL, 0); + if (lang != NULL) avio_printf(s->pb, " lang=\"%s\"", lang->value); + + if (codec->codec_type == AVMEDIA_TYPE_VIDEO) { + avio_printf(s->pb, " width=\"%d\"", codec->width); + avio_printf(s->pb, " height=\"%d\"", codec->height); + } else { + avio_printf(s->pb, " audioSamplingRate=\"%d\"", codec->sample_rate); + } + + avio_printf(s->pb, " bitstreamSwitching=\"%s\"", + boolean[bitstream_switching(s, as)]); + avio_printf(s->pb, " subsegmentAlignment=\"%s\"", + boolean[subsegment_alignment(s, as)]); + + for (i = 0; i < as->nb_streams; i++) { + AVDictionaryEntry *kf = av_dict_get(s->streams[as->streams[i]]->metadata, + CLUSTER_KEYFRAME, NULL, 0); + if (kf == NULL || !strncmp(kf->value, "0", 1)) subsegmentStartsWithSAP = 0; + } + avio_printf(s->pb, " subsegmentStartsWithSAP=\"%d\"", subsegmentStartsWithSAP); + avio_printf(s->pb, ">\n"); + + for (i = 0; i < as->nb_streams; i++) { + AVStream *stream = s->streams[as->streams[i]]; + AVDictionaryEntry *irange = av_dict_get(stream->metadata, INITIALIZATION_RANGE, NULL, 0); + AVDictionaryEntry *cues_start = av_dict_get(stream->metadata, CUES_START, NULL, 0); + AVDictionaryEntry *cues_end = av_dict_get(stream->metadata, CUES_END, NULL, 0); + AVDictionaryEntry *filename = av_dict_get(stream->metadata, FILENAME, NULL, 0); + AVDictionaryEntry *bandwidth = av_dict_get(stream->metadata, BANDWIDTH, NULL, 0); + if (irange == NULL || cues_start == NULL || cues_end == NULL || filename == NULL || + bandwidth == NULL) { + return -1; + } + avio_printf(s->pb, "<Representation id=\"%d\"", i); + avio_printf(s->pb, " bandwidth=\"%s\"", bandwidth->value); + avio_printf(s->pb, ">\n"); + avio_printf(s->pb, "<BaseURL>%s</BaseURL>\n", filename->value); + avio_printf(s->pb, "<SegmentBase\n"); + avio_printf(s->pb, " indexRange=\"%s-%s\">\n", cues_start->value, cues_end->value); + avio_printf(s->pb, "<Initialization\n"); + avio_printf(s->pb, " range=\"0-%s\" />\n", irange->value); + avio_printf(s->pb, "</SegmentBase>\n"); + avio_printf(s->pb, "</Representation>\n"); + } + avio_printf(s->pb, "</AdaptationSet>\n"); + return 0; +} + +static int to_integer(char *p, int len) +{ + int ret; + char *q = av_malloc(sizeof(char) * len); + if (q == NULL) return -1; + strncpy(q, p, len); + ret = atoi(q); + av_free(q); + return ret; +} + +static int parse_adaptation_sets(AVFormatContext *s) +{ + WebMDashMuxContext *w = s->priv_data; + char *p = w->adaptation_sets; + char *q; + enum { new_set, parsed_id, parsing_streams } state; + // syntax id=0,streams=0,1,2 id=1,streams=3,4 and so on + state = new_set; + while (p < w->adaptation_sets + strlen(w->adaptation_sets)) { + if (*p == ' ') + continue; + else if (state == new_set && !strncmp(p, "id=", 3)) { + w->as = av_realloc(w->as, sizeof(*w->as) * ++w->nb_as); + if (w->as == NULL) return -1; + w->as[w->nb_as - 1].nb_streams = 0; + w->as[w->nb_as - 1].streams = NULL; + p += 3; // consume "id=" + q = w->as[w->nb_as - 1].id; + while (*p != ',') *q++ = *p++; + *q = 0; + p++; + state = parsed_id; + } else if (state == parsed_id && !strncmp(p, "streams=", 8)) { + p += 8; // consume "streams=" + state = parsing_streams; + } else if (state == parsing_streams) { + struct AdaptationSet *as = &w->as[w->nb_as - 1]; + q = p; + while (*q != '\0' && *q != ',' && *q != ' ') q++; + as->streams = av_realloc(as->streams, sizeof(*as->streams) * ++as->nb_streams); + if (as->streams == NULL) return -1; + as->streams[as->nb_streams - 1] = to_integer(p, q - p); + if (as->streams[as->nb_streams - 1] < 0) return -1; + if (*q == '\0') break; + if (*q == ' ') state = new_set; + p = ++q; + } else { + return -1; + } + } + return 0; +} + +static int webm_dash_manifest_write_header(AVFormatContext *s) +{ + int i; + double start = 0.0; + WebMDashMuxContext *w = s->priv_data; + parse_adaptation_sets(s); + write_header(s); + avio_printf(s->pb, "<Period id=\"0\""); + avio_printf(s->pb, " start=\"PT%gS\"", start); + avio_printf(s->pb, " duration=\"PT%gS\"", get_duration(s)); + avio_printf(s->pb, " >\n"); + + for (i = 0; i < w->nb_as; i++) { + if (write_adaptation_set(s, i) < 0) return -1; + } + + avio_printf(s->pb, "</Period>\n"); + write_footer(s); + return 0; +} + +static int webm_dash_manifest_write_packet(AVFormatContext *s, AVPacket *pkt) +{ + return AVERROR_EOF; +} + +static int webm_dash_manifest_write_trailer(AVFormatContext *s) +{ + WebMDashMuxContext *w = s->priv_data; + int i; + for (i = 0; i < w->nb_as; i++) { + av_freep(&w->as[i].streams); + } + av_freep(&w->as); + return 0; +} + +#define OFFSET(x) offsetof(WebMDashMuxContext, x) +static const AVOption options[] = { + { "adaptation_sets", "Adaptation sets. Syntax: id=0,streams=0,1,2 id=1,streams=3,4 and so on", OFFSET(adaptation_sets), AV_OPT_TYPE_STRING, { 0 }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM }, + { NULL }, +}; + +#if CONFIG_WEBM_DASH_MANIFEST_MUXER +static const AVClass webm_dash_class = { + .class_name = "WebM DASH Manifest muxer", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + +AVOutputFormat ff_webm_dash_manifest_muxer = { + .name = "webm_dash_manifest", + .long_name = NULL_IF_CONFIG_SMALL("WebM DASH Manifest"), + .mime_type = "application/xml", + .extensions = "xml", + .priv_data_size = sizeof(WebMDashMuxContext), + .write_header = webm_dash_manifest_write_header, + .write_packet = webm_dash_manifest_write_packet, + .write_trailer = webm_dash_manifest_write_trailer, + .priv_class = &webm_dash_class, +}; +#endif |