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ffmpeg/libavformat/hlsenc.c

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/*
* Apple HTTP Live Streaming segmenter
* Copyright (c) 2012, Luca Barbato
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <float.h>
#include <stdint.h>
#include <config.h>
#if CONFIG_OPENSSL
#include <openssl/rand.h>
#endif
#include "libavutil/mathematics.h"
#include "libavutil/parseutils.h"
#include "libavutil/avstring.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/opt.h"
#include "libavutil/random_seed.h"
#include "libavutil/log.h"
#include "avformat.h"
#include "internal.h"
typedef struct ListEntry {
char name[1024];
int64_t duration; // segment duration in AV_TIME_BASE units
struct ListEntry *next;
} ListEntry;
typedef struct HLSContext {
const AVClass *class; // Class for private options.
unsigned number;
int64_t sequence;
int64_t start_sequence;
AVOutputFormat *oformat;
AVFormatContext *avf;
float time; // Set by a private option.
int size; // Set by a private option.
int wrap; // Set by a private option.
int version; // Set by a private option.
int allowcache;
int64_t recording_time;
int has_video;
// The following timestamps are in AV_TIME_BASE units.
int64_t start_pts;
int64_t end_pts;
int64_t duration; // last segment duration computed so far.
int nb_entries;
ListEntry *list;
ListEntry *end_list;
char *basename;
char *baseurl;
int encrypt; // Set by a private option.
char *key; // Set by a private option.
int key_len;
char *key_url; // Set by a private option.
char *iv; // Set by a private option.
int iv_len;
char *key_basename;
AVDictionary *enc_opts;
} HLSContext;
static int randomize(uint8_t *buf, int len)
{
#if CONFIG_OPENSSL
if (RAND_bytes(buf, len))
return 0;
return AVERROR(EIO);
#else
return AVERROR(ENOSYS);
#endif
}
static void free_encryption(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
av_dict_free(&hls->enc_opts);
av_freep(&hls->key_basename);
}
static int dict_set_bin(AVDictionary **dict, const char *key,
uint8_t *buf, size_t len)
{
char hex[33];
ff_data_to_hex(hex, buf, len, 0);
hex[32] = '\0';
return av_dict_set(dict, key, hex, 0);
}
static int setup_encryption(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
AVIOContext *out = NULL;
int len, ret;
uint8_t buf[16];
uint8_t *k = NULL;
len = strlen(hls->basename) + 4 + 1;
hls->key_basename = av_mallocz(len);
if (!hls->key_basename)
return AVERROR(ENOMEM);
av_strlcpy(hls->key_basename, hls->basename + 7, len);
av_strlcat(hls->key_basename, ".key", len);
if (hls->key) {
if (hls->key_len != 16) {
av_log(s, AV_LOG_ERROR,
"Invalid key size %d, expected 16-bytes hex-coded key\n",
hls->key_len);
return AVERROR(EINVAL);
}
if ((ret = dict_set_bin(&hls->enc_opts, "key", hls->key, hls->key_len)) < 0)
return ret;
k = hls->key;
} else {
if (hls->start_sequence < 0) {
ret = s->io_open(s, &out, hls->key_basename, AVIO_FLAG_READ, NULL);
if (ret < 0) {
av_log(s, AV_LOG_WARNING,
"Cannot recover the key, generating a new one.\n");
} else {
avio_read(out, buf, 16);
k = buf;
avio_close(out);
}
}
if (!k) {
if ((ret = randomize(buf, sizeof(buf))) < 0) {
av_log(s, AV_LOG_ERROR, "Cannot generate a strong random key\n");
return ret;
}
}
if ((ret = dict_set_bin(&hls->enc_opts, "key", buf, sizeof(buf))) < 0)
return ret;
k = buf;
}
if (hls->iv) {
if (hls->iv_len != 16) {
av_log(s, AV_LOG_ERROR,
"Invalid key size %d, expected 16-bytes hex-coded initialization vector\n",
hls->iv_len);
return AVERROR(EINVAL);
}
if ((ret = dict_set_bin(&hls->enc_opts, "iv", hls->iv, hls->iv_len)) < 0)
return ret;
}
if ((ret = s->io_open(s, &out, hls->key_basename, AVIO_FLAG_WRITE, NULL)) < 0)
return ret;
avio_write(out, k, 16);
avio_close(out);
return 0;
}
static int hls_mux_init(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
AVFormatContext *oc;
int i;
hls->avf = oc = avformat_alloc_context();
if (!oc)
return AVERROR(ENOMEM);
oc->oformat = hls->oformat;
oc->interrupt_callback = s->interrupt_callback;
oc->opaque = s->opaque;
oc->io_open = s->io_open;
oc->io_close = s->io_close;
for (i = 0; i < s->nb_streams; i++) {
AVStream *st;
if (!(st = avformat_new_stream(oc, NULL)))
return AVERROR(ENOMEM);
avcodec_parameters_copy(st->codecpar, s->streams[i]->codecpar);
st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
st->time_base = s->streams[i]->time_base;
}
return 0;
}
static int append_entry(HLSContext *hls, int64_t duration, const char *name)
{
ListEntry *en = av_malloc(sizeof(*en));
if (!en)
return AVERROR(ENOMEM);
av_strlcpy(en->name, name, sizeof(en->name));
en->duration = duration;
en->next = NULL;
if (!hls->list)
hls->list = en;
else
hls->end_list->next = en;
hls->end_list = en;
if (hls->nb_entries >= hls->size) {
en = hls->list;
hls->list = en->next;
av_free(en);
} else
hls->nb_entries++;
hls->sequence++;
return 0;
}
static void free_entries(HLSContext *hls)
{
ListEntry *p = hls->list, *en;
while(p) {
en = p;
p = p->next;
av_free(en);
}
}
static int hls_window(AVFormatContext *s, int last)
{
HLSContext *hls = s->priv_data;
ListEntry *en;
int64_t target_duration = 0;
int ret = 0;
AVIOContext *out = NULL;
char temp_filename[1024];
int64_t sequence = FFMAX(hls->start_sequence, hls->sequence - hls->size);
snprintf(temp_filename, sizeof(temp_filename), "%s.tmp", s->filename);
if ((ret = s->io_open(s, &out, temp_filename, AVIO_FLAG_WRITE, NULL)) < 0)
goto fail;
for (en = hls->list; en; en = en->next) {
if (target_duration < en->duration)
target_duration = en->duration;
}
avio_printf(out, "#EXTM3U\n");
avio_printf(out, "#EXT-X-VERSION:%d\n", hls->version);
if (hls->allowcache == 0 || hls->allowcache == 1) {
avio_printf(out, "#EXT-X-ALLOW-CACHE:%s\n", hls->allowcache == 0 ? "NO" : "YES");
}
avio_printf(out, "#EXT-X-TARGETDURATION:%"PRId64"\n",
av_rescale_rnd(target_duration, 1, AV_TIME_BASE,
AV_ROUND_UP));
avio_printf(out, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
av_log(s, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n",
sequence);
for (en = hls->list; en; en = en->next) {
if (hls->encrypt) {
char *key_url;
if (hls->key_url)
key_url = hls->key_url;
else
key_url = hls->baseurl;
avio_printf(out, "#EXT-X-KEY:METHOD=AES-128");
avio_printf(out, ",URI=\"");
if (key_url)
avio_printf(out, "%s", key_url);
avio_printf(out, "%s\"", av_basename(hls->key_basename));
if (hls->iv)
avio_printf(out, ",IV=\"0x%s\"", hls->iv);
avio_printf(out, "\n");
}
if (hls->version > 2)
avio_printf(out, "#EXTINF:%f\n",
(double)en->duration / AV_TIME_BASE);
else
avio_printf(out, "#EXTINF:%"PRId64",\n",
av_rescale(en->duration, 1, AV_TIME_BASE));
if (hls->baseurl)
avio_printf(out, "%s", hls->baseurl);
avio_printf(out, "%s\n", en->name);
}
if (last)
avio_printf(out, "#EXT-X-ENDLIST\n");
fail:
ff_format_io_close(s, &out);
if (ret >= 0)
ff_rename(temp_filename, s->filename);
return ret;
}
static int hls_start(AVFormatContext *s)
{
HLSContext *c = s->priv_data;
AVFormatContext *oc = c->avf;
int err = 0;
AVDictionary *opts = NULL;
if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
c->basename, c->wrap ? c->sequence % c->wrap : c->sequence) < 0)
return AVERROR(EINVAL);
c->number++;
if (c->encrypt) {
if ((err = av_dict_copy(&opts, c->enc_opts, 0)) < 0)
return err;
if (!c->iv) {
uint8_t iv[16] = { 0 };
char buf[33];
AV_WB64(iv + 8, c->sequence);
ff_data_to_hex(buf, iv, sizeof(iv), 0);
buf[32] = '\0';
if ((err = av_dict_set(&opts, "iv", buf, 0)) < 0)
goto fail;
}
}
if ((err = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, &opts)) < 0)
return err;
if (oc->oformat->priv_class && oc->priv_data)
av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
fail:
av_dict_free(&opts);
return err;
}
static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
{
int len = ff_get_line(s, buf, maxlen);
while (len > 0 && av_isspace(buf[len - 1]))
buf[--len] = '\0';
return len;
}
static int hls_recover(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
char line[1024];
AVIOContext *io;
const char *ptr;
int ret, is_segment = 0;
int64_t duration = 0;
ret = s->io_open(s, &io, s->filename, AVIO_FLAG_READ, NULL);
if (ret < 0) {
av_log(s, AV_LOG_WARNING,
"Cannot recover the playlist, generating a new one.\n");
hls->start_sequence = 0;
hls->sequence = 0;
return 0;
}
read_chomp_line(io, line, sizeof(line));
if (strcmp(line, "#EXTM3U")) {
av_log(s, AV_LOG_ERROR,
"The playlist file is present but unparsable."
" Please remove it.\n");
return AVERROR_INVALIDDATA;
}
while (!io->eof_reached) {
read_chomp_line(io, line, sizeof(line));
if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
hls->sequence = hls->start_sequence = atoi(ptr);
} else if (av_strstart(line, "#EXTINF:", &ptr)) {
is_segment = 1;
duration = atof(ptr) * AV_TIME_BASE;
} else if (av_strstart(line, "#", NULL)) {
continue;
} else if (line[0]) {
if (is_segment) {
append_entry(hls, duration, av_basename(line));
is_segment = 0;
}
}
}
return 0;
}
static int hls_setup(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
const char *pattern = "%d.ts";
int basename_size = strlen(s->filename) + strlen(pattern) + 1;
char *p;
int ret;
if (hls->encrypt)
basename_size += 7;
hls->basename = av_mallocz(basename_size);
if (!hls->basename)
return AVERROR(ENOMEM);
// TODO: support protocol nesting?
if (hls->encrypt)
strcpy(hls->basename, "crypto:");
av_strlcat(hls->basename, s->filename, basename_size);
p = strrchr(hls->basename, '.');
if (p)
*p = '\0';
if (hls->encrypt) {
ret = setup_encryption(s);
if (ret < 0)
return ret;
}
if (hls->start_sequence < 0) {
ret = hls_recover(s);
if (ret < 0)
return ret;
}
av_strlcat(hls->basename, pattern, basename_size);
return 0;
}
static int hls_write_header(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
int ret, i;
hls->sequence = hls->start_sequence;
hls->recording_time = hls->time * AV_TIME_BASE;
hls->start_pts = AV_NOPTS_VALUE;
for (i = 0; i < s->nb_streams; i++)
hls->has_video +=
s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO;
if (hls->has_video > 1)
av_log(s, AV_LOG_WARNING,
"More than a single video stream present, "
"expect issues decoding it.\n");
hls->oformat = av_guess_format("mpegts", NULL, NULL);
if (!hls->oformat) {
ret = AVERROR_MUXER_NOT_FOUND;
goto fail;
}
if ((ret = hls_setup(s)) < 0)
goto fail;
if ((ret = hls_mux_init(s)) < 0)
goto fail;
if ((ret = hls_start(s)) < 0)
goto fail;
if ((ret = avformat_write_header(hls->avf, NULL)) < 0)
return ret;
fail:
if (ret) {
av_free(hls->basename);
if (hls->avf)
avformat_free_context(hls->avf);
free_encryption(s);
}
return ret;
}
static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
{
HLSContext *hls = s->priv_data;
AVFormatContext *oc = hls->avf;
AVStream *st = s->streams[pkt->stream_index];
int64_t end_pts = hls->recording_time * hls->number;
int64_t pts = av_rescale_q(pkt->pts, st->time_base, AV_TIME_BASE_Q);
int ret, can_split = 1;
if (hls->start_pts == AV_NOPTS_VALUE) {
hls->start_pts = pts;
hls->end_pts = pts;
}
if (hls->has_video) {
can_split = st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
pkt->flags & AV_PKT_FLAG_KEY;
}
if (pkt->pts == AV_NOPTS_VALUE)
can_split = 0;
else
hls->duration = pts - hls->end_pts;
if (can_split && pts - hls->start_pts >= end_pts) {
ret = append_entry(hls, hls->duration, av_basename(hls->avf->filename));
if (ret)
return ret;
hls->end_pts = pts;
hls->duration = 0;
av_write_frame(oc, NULL); /* Flush any buffered data */
ff_format_io_close(s, &oc->pb);
ret = hls_start(s);
if (ret)
return ret;
oc = hls->avf;
if ((ret = hls_window(s, 0)) < 0)
return ret;
}
ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
return ret;
}
static int hls_write_trailer(struct AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
AVFormatContext *oc = hls->avf;
av_write_trailer(oc);
ff_format_io_close(s, &oc->pb);
avformat_free_context(oc);
av_free(hls->basename);
append_entry(hls, hls->duration, av_basename(hls->avf->filename));
hls_window(s, 1);
free_entries(hls);
free_encryption(s);
return 0;
}
#define OFFSET(x) offsetof(HLSContext, x)
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{"start_number", "first number in the sequence", OFFSET(start_sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, -1, INT64_MAX, E, "start_number"},
{"recover", "If there is already a m3u8 file in the path, populate the sequence from it", 0, AV_OPT_TYPE_CONST, {.i64 = -1}, 0, 0, E, "start_number"},
{"hls_time", "segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
{"hls_list_size", "maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
{"hls_wrap", "number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
{"hls_allow_cache", "explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments", OFFSET(allowcache), AV_OPT_TYPE_INT, {.i64 = -1}, INT_MIN, INT_MAX, E},
{"hls_base_url", "url to prepend to each playlist entry", OFFSET(baseurl), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
{"hls_version", "protocol version", OFFSET(version), AV_OPT_TYPE_INT, {.i64 = 3}, 2, 3, E},
{"hls_enc", "AES128 encryption support", OFFSET(encrypt), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, E},
{"hls_enc_key", "use the specified hex-coded 16byte key to encrypt the segments", OFFSET(key), AV_OPT_TYPE_BINARY, .flags = E},
{"hls_enc_key_url", "url to access the key to decrypt the segments", OFFSET(key_url), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
{"hls_enc_iv", "use the specified hex-coded 16byte initialization vector", OFFSET(iv), AV_OPT_TYPE_BINARY, .flags = E},
{ NULL },
};
static const AVClass hls_class = {
.class_name = "hls muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_hls_muxer = {
.name = "hls",
.long_name = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
.extensions = "m3u8",
.priv_data_size = sizeof(HLSContext),
.audio_codec = AV_CODEC_ID_AAC,
.video_codec = AV_CODEC_ID_H264,
.flags = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
.write_header = hls_write_header,
.write_packet = hls_write_packet,
.write_trailer = hls_write_trailer,
.priv_class = &hls_class,
};
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