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FFmpeg/libavformat/webmdashenc.c
Andreas Rheinhardt 325c901430 avformat/webmdashenc: Avoid allocation for parsing a number
In order to parse a number from a string, the WebM DASH manifest muxer
would duplicate (via heap-allocation) the part of the string that
contains the number, then read the number via atoi() and then free the
duplicate again. This has been replaced by simply using strtoll() (which
in contrast to atoi() has defined behaviour when the number is not
representable).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-05-23 06:05:16 +02:00

567 lines
22 KiB
C

/*
* 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
* ISO DASH Specification:
* http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip
*/
#include <float.h>
#include <stdint.h>
#include <string.h>
#include "avformat.h"
#include "matroska.h"
#include "libavutil/avstring.h"
#include "libavutil/dict.h"
#include "libavutil/opt.h"
#include "libavutil/time_internal.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;
int representation_id;
int is_live;
int chunk_start_index;
int chunk_duration;
char *utc_timing_url;
double time_shift_buffer_depth;
int minimum_update_period;
} WebMDashMuxContext;
static const char *get_codec_name(int codec_id)
{
return avcodec_descriptor_get(codec_id)->name;
}
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 || atof(duration->value) < 0) continue;
if (atof(duration->value) > max) max = atof(duration->value);
}
return max / 1000;
}
static int write_header(AVFormatContext *s)
{
WebMDashMuxContext *w = s->priv_data;
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=\"%s\"\n", w->is_live ? "dynamic" : "static");
if (!w->is_live) {
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=\"%s\"%s",
w->is_live ? "urn:mpeg:dash:profile:isoff-live:2011" : "urn:webm:dash:profile:webm-on-demand:2012",
w->is_live ? "\n" : ">\n");
if (w->is_live) {
time_t local_time = time(NULL);
struct tm gmt_buffer;
struct tm *gmt = gmtime_r(&local_time, &gmt_buffer);
char gmt_iso[21];
if (!strftime(gmt_iso, 21, "%Y-%m-%dT%H:%M:%SZ", gmt)) {
return AVERROR_UNKNOWN;
}
if (s->flags & AVFMT_FLAG_BITEXACT) {
av_strlcpy(gmt_iso, "", 1);
}
avio_printf(s->pb, " availabilityStartTime=\"%s\"\n", gmt_iso);
avio_printf(s->pb, " timeShiftBufferDepth=\"PT%gS\"\n", w->time_shift_buffer_depth);
avio_printf(s->pb, " minimumUpdatePeriod=\"PT%dS\"", w->minimum_update_period);
avio_printf(s->pb, ">\n");
if (w->utc_timing_url) {
avio_printf(s->pb, "<UTCTiming\n");
avio_printf(s->pb, " schemeIdUri=\"urn:mpeg:dash:utc:http-iso:2014\"\n");
avio_printf(s->pb, " value=\"%s\"/>\n", w->utc_timing_url);
}
}
return 0;
}
static void write_footer(AVFormatContext *s)
{
avio_printf(s->pb, "</MPD>\n");
}
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) 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 || 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);
AVCodecParameters *gold_par = s->streams[as->streams[0]]->codecpar;
if (!gold_track_num) 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);
AVCodecParameters *par = s->streams[as->streams[i]]->codecpar;
if (!track_num ||
strncmp(gold_track_num->value, track_num->value, strlen(gold_track_num->value)) ||
gold_par->codec_id != par->codec_id ||
gold_par->extradata_size != par->extradata_size ||
memcmp(gold_par->extradata, par->extradata, par->extradata_size)) {
return 0;
}
}
return 1;
}
/*
* Writes a Representation within an Adaptation Set. Returns 0 on success and
* < 0 on failure.
*/
static int write_representation(AVFormatContext *s, AVStream *stream, char *id,
int output_width, int output_height,
int output_sample_rate) {
WebMDashMuxContext *w = s->priv_data;
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);
const char *bandwidth_str;
if ((w->is_live && (!filename)) ||
(!w->is_live && (!irange || !cues_start || !cues_end || !filename || !bandwidth))) {
return AVERROR_INVALIDDATA;
}
avio_printf(s->pb, "<Representation id=\"%s\"", id);
// if bandwidth for live was not provided, use a default
if (w->is_live && !bandwidth) {
bandwidth_str = (stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) ? "128000" : "1000000";
} else {
bandwidth_str = bandwidth->value;
}
avio_printf(s->pb, " bandwidth=\"%s\"", bandwidth_str);
if (stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && output_width)
avio_printf(s->pb, " width=\"%d\"", stream->codecpar->width);
if (stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && output_height)
avio_printf(s->pb, " height=\"%d\"", stream->codecpar->height);
if (stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && output_sample_rate)
avio_printf(s->pb, " audioSamplingRate=\"%d\"", stream->codecpar->sample_rate);
if (w->is_live) {
// For live streams, Codec and Mime Type always go in the Representation tag.
avio_printf(s->pb, " codecs=\"%s\"", get_codec_name(stream->codecpar->codec_id));
avio_printf(s->pb, " mimeType=\"%s/webm\"",
stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
// For live streams, subsegments always start with key frames. So this
// is always 1.
avio_printf(s->pb, " startsWithSAP=\"1\"");
avio_printf(s->pb, ">");
} else {
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");
return 0;
}
/*
* Checks if width of all streams are the same. Returns 1 if true, 0 otherwise.
*/
static int check_matching_width(AVFormatContext *s, AdaptationSet *as) {
int first_width, i;
if (as->nb_streams < 2) return 1;
first_width = s->streams[as->streams[0]]->codecpar->width;
for (i = 1; i < as->nb_streams; i++)
if (first_width != s->streams[as->streams[i]]->codecpar->width)
return 0;
return 1;
}
/*
* Checks if height of all streams are the same. Returns 1 if true, 0 otherwise.
*/
static int check_matching_height(AVFormatContext *s, AdaptationSet *as) {
int first_height, i;
if (as->nb_streams < 2) return 1;
first_height = s->streams[as->streams[0]]->codecpar->height;
for (i = 1; i < as->nb_streams; i++)
if (first_height != s->streams[as->streams[i]]->codecpar->height)
return 0;
return 1;
}
/*
* Checks if sample rate of all streams are the same. Returns 1 if true, 0 otherwise.
*/
static int check_matching_sample_rate(AVFormatContext *s, AdaptationSet *as) {
int first_sample_rate, i;
if (as->nb_streams < 2) return 1;
first_sample_rate = s->streams[as->streams[0]]->codecpar->sample_rate;
for (i = 1; i < as->nb_streams; i++)
if (first_sample_rate != s->streams[as->streams[i]]->codecpar->sample_rate)
return 0;
return 1;
}
static void free_adaptation_sets(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);
w->nb_as = 0;
}
/*
* Parses a live header filename and computes the representation id,
* initialization pattern and the media pattern. Pass NULL if you don't want to
* compute any of those 3. Returns 0 on success and non-zero on failure.
*
* Name of the header file should conform to the following pattern:
* <file_description>_<representation_id>.hdr where <file_description> can be
* anything. The chunks should be named according to the following pattern:
* <file_description>_<representation_id>_<chunk_number>.chk
*/
static int parse_filename(char *filename, char **representation_id,
char **initialization_pattern, char **media_pattern) {
char *underscore_pos = NULL;
char *period_pos = NULL;
char *temp_pos = NULL;
char *filename_str = av_strdup(filename);
int ret = 0;
if (!filename_str) {
ret = AVERROR(ENOMEM);
goto end;
}
temp_pos = av_stristr(filename_str, "_");
while (temp_pos) {
underscore_pos = temp_pos + 1;
temp_pos = av_stristr(temp_pos + 1, "_");
}
if (!underscore_pos) {
ret = AVERROR_INVALIDDATA;
goto end;
}
period_pos = av_stristr(underscore_pos, ".");
if (!period_pos) {
ret = AVERROR_INVALIDDATA;
goto end;
}
*(underscore_pos - 1) = 0;
if (representation_id) {
*representation_id = av_malloc(period_pos - underscore_pos + 1);
if (!(*representation_id)) {
ret = AVERROR(ENOMEM);
goto end;
}
av_strlcpy(*representation_id, underscore_pos, period_pos - underscore_pos + 1);
}
if (initialization_pattern) {
*initialization_pattern = av_asprintf("%s_$RepresentationID$.hdr",
filename_str);
if (!(*initialization_pattern)) {
ret = AVERROR(ENOMEM);
goto end;
}
}
if (media_pattern) {
*media_pattern = av_asprintf("%s_$RepresentationID$_$Number$.chk",
filename_str);
if (!(*media_pattern)) {
ret = AVERROR(ENOMEM);
goto end;
}
}
end:
av_freep(&filename_str);
return ret;
}
/*
* 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];
AVCodecParameters *par = s->streams[as->streams[0]]->codecpar;
AVDictionaryEntry *lang;
int i;
static const char boolean[2][6] = { "false", "true" };
int subsegmentStartsWithSAP = 1;
// Width, Height and Sample Rate will go in the AdaptationSet tag if they
// are the same for all contained Representations. otherwise, they will go
// on their respective Representation tag. For live streams, they always go
// in the Representation tag.
int width_in_as = 1, height_in_as = 1, sample_rate_in_as = 1;
if (par->codec_type == AVMEDIA_TYPE_VIDEO) {
width_in_as = !w->is_live && check_matching_width(s, as);
height_in_as = !w->is_live && check_matching_height(s, as);
} else {
sample_rate_in_as = !w->is_live && check_matching_sample_rate(s, as);
}
avio_printf(s->pb, "<AdaptationSet id=\"%s\"", as->id);
avio_printf(s->pb, " mimeType=\"%s/webm\"",
par->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
avio_printf(s->pb, " codecs=\"%s\"", get_codec_name(par->codec_id));
lang = av_dict_get(s->streams[as->streams[0]]->metadata, "language", NULL, 0);
if (lang) avio_printf(s->pb, " lang=\"%s\"", lang->value);
if (par->codec_type == AVMEDIA_TYPE_VIDEO && width_in_as)
avio_printf(s->pb, " width=\"%d\"", par->width);
if (par->codec_type == AVMEDIA_TYPE_VIDEO && height_in_as)
avio_printf(s->pb, " height=\"%d\"", par->height);
if (par->codec_type == AVMEDIA_TYPE_AUDIO && sample_rate_in_as)
avio_printf(s->pb, " audioSamplingRate=\"%d\"", par->sample_rate);
avio_printf(s->pb, " bitstreamSwitching=\"%s\"",
boolean[bitstream_switching(s, as)]);
avio_printf(s->pb, " subsegmentAlignment=\"%s\"",
boolean[w->is_live || 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 (!w->is_live && (!kf || !strncmp(kf->value, "0", 1))) subsegmentStartsWithSAP = 0;
}
avio_printf(s->pb, " subsegmentStartsWithSAP=\"%d\"", subsegmentStartsWithSAP);
avio_printf(s->pb, ">\n");
if (w->is_live) {
AVDictionaryEntry *filename =
av_dict_get(s->streams[as->streams[0]]->metadata, FILENAME, NULL, 0);
char *initialization_pattern = NULL;
char *media_pattern = NULL;
int ret = parse_filename(filename->value, NULL, &initialization_pattern,
&media_pattern);
if (ret) return ret;
avio_printf(s->pb, "<ContentComponent id=\"1\" type=\"%s\"/>\n",
par->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
avio_printf(s->pb, "<SegmentTemplate");
avio_printf(s->pb, " timescale=\"1000\"");
avio_printf(s->pb, " duration=\"%d\"", w->chunk_duration);
avio_printf(s->pb, " media=\"%s\"", media_pattern);
avio_printf(s->pb, " startNumber=\"%d\"", w->chunk_start_index);
avio_printf(s->pb, " initialization=\"%s\"", initialization_pattern);
avio_printf(s->pb, "/>\n");
av_free(initialization_pattern);
av_free(media_pattern);
}
for (i = 0; i < as->nb_streams; i++) {
char *representation_id = NULL;
int ret;
if (w->is_live) {
AVDictionaryEntry *filename =
av_dict_get(s->streams[as->streams[i]]->metadata, FILENAME, NULL, 0);
if (!filename)
return AVERROR(EINVAL);
if (ret = parse_filename(filename->value, &representation_id, NULL, NULL))
return ret;
} else {
representation_id = av_asprintf("%d", w->representation_id++);
if (!representation_id) return AVERROR(ENOMEM);
}
ret = write_representation(s, s->streams[as->streams[i]],
representation_id, !width_in_as,
!height_in_as, !sample_rate_in_as);
av_free(representation_id);
if (ret) return ret;
}
avio_printf(s->pb, "</AdaptationSet>\n");
return 0;
}
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;
if (!w->adaptation_sets) {
av_log(s, AV_LOG_ERROR, "The 'adaptation_sets' option must be set.\n");
return AVERROR(EINVAL);
}
// 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)) {
void *mem = av_realloc(w->as, sizeof(*w->as) * (w->nb_as + 1));
const char *comma;
if (mem == NULL)
return AVERROR(ENOMEM);
w->as = mem;
++w->nb_as;
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;
comma = strchr(p, ',');
if (!comma || comma - p >= sizeof(w->as[w->nb_as - 1].id)) {
av_log(s, AV_LOG_ERROR, "'id' in 'adaptation_sets' is malformed.\n");
return AVERROR(EINVAL);
}
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];
int ret = av_reallocp_array(&as->streams, ++as->nb_streams,
sizeof(*as->streams));
if (ret < 0)
return ret;
q = p;
while (*q != '\0' && *q != ',' && *q != ' ') q++;
as->streams[as->nb_streams - 1] = strtoll(p, NULL, 10);
if (as->streams[as->nb_streams - 1] < 0 ||
as->streams[as->nb_streams - 1] >= s->nb_streams) {
av_log(s, AV_LOG_ERROR, "Invalid value for 'streams' in adapation_sets.\n");
return AVERROR(EINVAL);
}
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;
int ret;
WebMDashMuxContext *w = s->priv_data;
for (unsigned i = 0; i < s->nb_streams; i++) {
enum AVCodecID codec_id = s->streams[i]->codecpar->codec_id;
if (codec_id != AV_CODEC_ID_VP8 && codec_id != AV_CODEC_ID_VP9 &&
codec_id != AV_CODEC_ID_VORBIS && codec_id != AV_CODEC_ID_OPUS)
return AVERROR(EINVAL);
}
ret = parse_adaptation_sets(s);
if (ret < 0) {
goto fail;
}
ret = write_header(s);
if (ret < 0) {
goto fail;
}
avio_printf(s->pb, "<Period id=\"0\"");
avio_printf(s->pb, " start=\"PT%gS\"", start);
if (!w->is_live) {
avio_printf(s->pb, " duration=\"PT%gS\"", get_duration(s));
}
avio_printf(s->pb, " >\n");
for (i = 0; i < w->nb_as; i++) {
ret = write_adaptation_set(s, i);
if (ret < 0) {
goto fail;
}
}
avio_printf(s->pb, "</Period>\n");
write_footer(s);
fail:
free_adaptation_sets(s);
return ret < 0 ? ret : 0;
}
static int webm_dash_manifest_write_packet(AVFormatContext *s, AVPacket *pkt)
{
return AVERROR_EOF;
}
#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 },
{ "live", "create a live stream manifest", OFFSET(is_live), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
{ "chunk_start_index", "start index of the chunk", OFFSET(chunk_start_index), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ "chunk_duration_ms", "duration of each chunk (in milliseconds)", OFFSET(chunk_duration), AV_OPT_TYPE_INT, {.i64 = 1000}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ "utc_timing_url", "URL of the page that will return the UTC timestamp in ISO format", OFFSET(utc_timing_url), AV_OPT_TYPE_STRING, { 0 }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
{ "time_shift_buffer_depth", "Smallest time (in seconds) shifting buffer for which any Representation is guaranteed to be available.", OFFSET(time_shift_buffer_depth), AV_OPT_TYPE_DOUBLE, { .dbl = 60.0 }, 1.0, DBL_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ "minimum_update_period", "Minimum Update Period (in seconds) of the manifest.", OFFSET(minimum_update_period), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ NULL },
};
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,
.priv_class = &webm_dash_class,
};