ffmpeg/libavformat/smoothstreamingenc.c

654 lines
23 KiB
C

/*
* Live smooth streaming fragmenter
* Copyright (c) 2012 Martin Storsjo
*
* 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
*/
#include "config.h"
#include <float.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "os_support.h"
#include "avc.h"
#include "url.h"
#include "isom.h"
#include "libavutil/opt.h"
#include "libavutil/avstring.h"
#include "libavutil/file.h"
#include "libavutil/mathematics.h"
#include "libavutil/intreadwrite.h"
typedef struct Fragment {
char file[1024];
char infofile[1024];
int64_t start_time, duration;
int n;
int64_t start_pos, size;
} Fragment;
typedef struct OutputStream {
AVFormatContext *ctx;
char dirname[1024];
uint8_t iobuf[32768];
URLContext *out; // Current output stream where all output is written
URLContext *out2; // Auxiliary output stream where all output is also written
URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
int64_t tail_pos, cur_pos, cur_start_pos;
int packets_written;
const char *stream_type_tag;
int nb_fragments, fragments_size, fragment_index;
Fragment **fragments;
const char *fourcc;
char *private_str;
int packet_size;
int audio_tag;
} OutputStream;
typedef struct SmoothStreamingContext {
const AVClass *class; /* Class for private options. */
int window_size;
int extra_window_size;
int lookahead_count;
int min_frag_duration;
int remove_at_exit;
OutputStream *streams;
int has_video, has_audio;
int nb_fragments;
} SmoothStreamingContext;
static int ism_write(void *opaque, uint8_t *buf, int buf_size)
{
OutputStream *os = opaque;
if (os->out)
ffurl_write(os->out, buf, buf_size);
if (os->out2)
ffurl_write(os->out2, buf, buf_size);
os->cur_pos += buf_size;
if (os->cur_pos >= os->tail_pos)
os->tail_pos = os->cur_pos;
return buf_size;
}
static int64_t ism_seek(void *opaque, int64_t offset, int whence)
{
OutputStream *os = opaque;
int i;
if (whence != SEEK_SET)
return AVERROR(ENOSYS);
if (os->tail_out) {
ffurl_closep(&os->out);
ffurl_closep(&os->out2);
os->out = os->tail_out;
os->tail_out = NULL;
}
if (offset >= os->cur_start_pos) {
if (os->out)
ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
os->cur_pos = offset;
return offset;
}
for (i = os->nb_fragments - 1; i >= 0; i--) {
Fragment *frag = os->fragments[i];
if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
int ret;
AVDictionary *opts = NULL;
os->tail_out = os->out;
av_dict_set(&opts, "truncate", "0", 0);
ret = ffurl_open_whitelist(&os->out, frag->file, AVIO_FLAG_WRITE,
&os->ctx->interrupt_callback, &opts, os->ctx->protocol_whitelist, os->ctx->protocol_blacklist, NULL);
av_dict_free(&opts);
if (ret < 0) {
os->out = os->tail_out;
os->tail_out = NULL;
return ret;
}
av_dict_set(&opts, "truncate", "0", 0);
ffurl_open_whitelist(&os->out2, frag->infofile, AVIO_FLAG_WRITE,
&os->ctx->interrupt_callback, &opts, os->ctx->protocol_whitelist, os->ctx->protocol_blacklist, NULL);
av_dict_free(&opts);
ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
if (os->out2)
ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
os->cur_pos = offset;
return offset;
}
}
return AVERROR(EIO);
}
static void get_private_data(OutputStream *os)
{
AVCodecParameters *par = os->ctx->streams[0]->codecpar;
uint8_t *ptr = par->extradata;
int size = par->extradata_size;
int i;
if (par->codec_id == AV_CODEC_ID_H264) {
ff_avc_write_annexb_extradata(ptr, &ptr, &size);
if (!ptr)
ptr = par->extradata;
}
if (!ptr)
return;
os->private_str = av_mallocz(2*size + 1);
if (!os->private_str)
goto fail;
for (i = 0; i < size; i++)
snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
fail:
if (ptr != par->extradata)
av_free(ptr);
}
static void ism_free(AVFormatContext *s)
{
SmoothStreamingContext *c = s->priv_data;
int i, j;
if (!c->streams)
return;
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
ffurl_closep(&os->out);
ffurl_closep(&os->out2);
ffurl_closep(&os->tail_out);
if (os->ctx && os->ctx->pb)
avio_context_free(&os->ctx->pb);
avformat_free_context(os->ctx);
av_freep(&os->private_str);
for (j = 0; j < os->nb_fragments; j++)
av_freep(&os->fragments[j]);
av_freep(&os->fragments);
}
av_freep(&c->streams);
}
static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
{
int removed = 0, i, start = 0;
if (os->nb_fragments <= 0)
return;
if (os->fragments[0]->n > 0)
removed = 1;
if (final)
skip = 0;
if (window_size)
start = FFMAX(os->nb_fragments - skip - window_size, 0);
for (i = start; i < os->nb_fragments - skip; i++) {
Fragment *frag = os->fragments[i];
if (!final || removed)
avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
else
avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
}
}
static int write_manifest(AVFormatContext *s, int final)
{
SmoothStreamingContext *c = s->priv_data;
AVIOContext *out;
char filename[1024], temp_filename[1024];
int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
int64_t duration = 0;
snprintf(filename, sizeof(filename), "%s/Manifest", s->url);
snprintf(temp_filename, sizeof(temp_filename), "%s/Manifest.tmp", s->url);
ret = s->io_open(s, &out, temp_filename, AVIO_FLAG_WRITE, NULL);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
return ret;
}
avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
if (os->nb_fragments > 0) {
Fragment *last = os->fragments[os->nb_fragments - 1];
duration = last->start_time + last->duration;
}
if (s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
video_chunks = os->nb_fragments;
video_streams++;
} else {
audio_chunks = os->nb_fragments;
audio_streams++;
}
}
if (!final) {
duration = 0;
video_chunks = audio_chunks = 0;
}
if (c->window_size) {
video_chunks = FFMIN(video_chunks, c->window_size);
audio_chunks = FFMIN(audio_chunks, c->window_size);
}
avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
if (!final)
avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
avio_printf(out, ">\n");
if (c->has_video) {
int last = -1, index = 0;
avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO)
continue;
last = i;
avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%"PRId64"\" FourCC=\"%s\" MaxWidth=\"%d\" MaxHeight=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codecpar->bit_rate, os->fourcc, s->streams[i]->codecpar->width, s->streams[i]->codecpar->height, os->private_str);
index++;
}
output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
avio_printf(out, "</StreamIndex>\n");
}
if (c->has_audio) {
int last = -1, index = 0;
avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_AUDIO)
continue;
last = i;
avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%"PRId64"\" FourCC=\"%s\" SamplingRate=\"%d\" Channels=\"%d\" BitsPerSample=\"16\" PacketSize=\"%d\" AudioTag=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codecpar->bit_rate, os->fourcc, s->streams[i]->codecpar->sample_rate, s->streams[i]->codecpar->channels, os->packet_size, os->audio_tag, os->private_str);
index++;
}
output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
avio_printf(out, "</StreamIndex>\n");
}
avio_printf(out, "</SmoothStreamingMedia>\n");
avio_flush(out);
ff_format_io_close(s, &out);
return ff_rename(temp_filename, filename, s);
}
static int ism_write_header(AVFormatContext *s)
{
SmoothStreamingContext *c = s->priv_data;
int ret = 0, i;
const AVOutputFormat *oformat;
if (mkdir(s->url, 0777) == -1 && errno != EEXIST) {
av_log(s, AV_LOG_ERROR, "mkdir failed\n");
return AVERROR(errno);
}
oformat = av_guess_format("ismv", NULL, NULL);
if (!oformat) {
return AVERROR_MUXER_NOT_FOUND;
}
c->streams = av_calloc(s->nb_streams, sizeof(*c->streams));
if (!c->streams) {
return AVERROR(ENOMEM);
}
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
AVFormatContext *ctx;
AVStream *st;
AVDictionary *opts = NULL;
if (!s->streams[i]->codecpar->bit_rate) {
av_log(s, AV_LOG_WARNING, "No bit rate set for stream %d\n", i);
// create a tmp name for the directory of fragments
snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(Tmp_%d)", s->url, i);
} else {
snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%"PRId64")", s->url, s->streams[i]->codecpar->bit_rate);
}
if (mkdir(os->dirname, 0777) == -1 && errno != EEXIST) {
av_log(s, AV_LOG_ERROR, "mkdir failed\n");
return AVERROR(errno);
}
os->ctx = ctx = avformat_alloc_context();
if (!ctx) {
return AVERROR(ENOMEM);
}
if ((ret = ff_copy_whiteblacklists(ctx, s)) < 0)
return ret;
ctx->oformat = oformat;
ctx->interrupt_callback = s->interrupt_callback;
if (!(st = avformat_new_stream(ctx, 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;
ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, ism_write, ism_seek);
if (!ctx->pb) {
return AVERROR(ENOMEM);
}
av_dict_set_int(&opts, "ism_lookahead", c->lookahead_count, 0);
av_dict_set(&opts, "movflags", "frag_custom", 0);
ret = avformat_write_header(ctx, &opts);
av_dict_free(&opts);
if (ret < 0) {
return ret;
}
avio_flush(ctx->pb);
s->streams[i]->time_base = st->time_base;
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
c->has_video = 1;
os->stream_type_tag = "video";
if (st->codecpar->codec_id == AV_CODEC_ID_H264) {
os->fourcc = "H264";
} else if (st->codecpar->codec_id == AV_CODEC_ID_VC1) {
os->fourcc = "WVC1";
} else {
av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
return AVERROR(EINVAL);
}
} else {
c->has_audio = 1;
os->stream_type_tag = "audio";
if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
os->fourcc = "AACL";
os->audio_tag = 0xff;
} else if (st->codecpar->codec_id == AV_CODEC_ID_WMAPRO) {
os->fourcc = "WMAP";
os->audio_tag = 0x0162;
} else {
av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
return AVERROR(EINVAL);
}
os->packet_size = st->codecpar->block_align ? st->codecpar->block_align : 4;
}
get_private_data(os);
}
if (!c->has_video && c->min_frag_duration <= 0) {
av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
return AVERROR(EINVAL);
}
ret = write_manifest(s, 0);
if (ret < 0)
return ret;
return 0;
}
static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
{
AVIOContext *in;
int ret;
uint32_t len;
if ((ret = s->io_open(s, &in, filename, AVIO_FLAG_READ, NULL)) < 0)
return ret;
ret = AVERROR(EIO);
*moof_size = avio_rb32(in);
if (*moof_size < 8 || *moof_size > size)
goto fail;
if (avio_rl32(in) != MKTAG('m','o','o','f'))
goto fail;
len = avio_rb32(in);
if (len > *moof_size)
goto fail;
if (avio_rl32(in) != MKTAG('m','f','h','d'))
goto fail;
avio_seek(in, len - 8, SEEK_CUR);
avio_rb32(in); /* traf size */
if (avio_rl32(in) != MKTAG('t','r','a','f'))
goto fail;
while (avio_tell(in) < *moof_size) {
uint32_t len = avio_rb32(in);
uint32_t tag = avio_rl32(in);
int64_t end = avio_tell(in) + len - 8;
if (len < 8 || len >= *moof_size)
goto fail;
if (tag == MKTAG('u','u','i','d')) {
static const uint8_t tfxd[] = {
0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
};
uint8_t uuid[16];
avio_read(in, uuid, 16);
if (!memcmp(uuid, tfxd, 16) && len >= 8 + 16 + 4 + 16) {
avio_seek(in, 4, SEEK_CUR);
*start_ts = avio_rb64(in);
*duration = avio_rb64(in);
ret = 0;
break;
}
}
avio_seek(in, end, SEEK_SET);
}
fail:
ff_format_io_close(s, &in);
return ret;
}
static int add_fragment(OutputStream *os, const char *file, const char *infofile, int64_t start_time, int64_t duration, int64_t start_pos, int64_t size)
{
int err;
Fragment *frag;
if (os->nb_fragments >= os->fragments_size) {
os->fragments_size = (os->fragments_size + 1) * 2;
if ((err = av_reallocp_array(&os->fragments, sizeof(*os->fragments),
os->fragments_size)) < 0) {
os->fragments_size = 0;
os->nb_fragments = 0;
return err;
}
}
frag = av_mallocz(sizeof(*frag));
if (!frag)
return AVERROR(ENOMEM);
av_strlcpy(frag->file, file, sizeof(frag->file));
av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
frag->start_time = start_time;
frag->duration = duration;
frag->start_pos = start_pos;
frag->size = size;
frag->n = os->fragment_index;
os->fragments[os->nb_fragments++] = frag;
os->fragment_index++;
return 0;
}
static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
{
AVIOContext *in, *out;
int ret = 0;
if ((ret = s->io_open(s, &in, infile, AVIO_FLAG_READ, NULL)) < 0)
return ret;
if ((ret = s->io_open(s, &out, outfile, AVIO_FLAG_WRITE, NULL)) < 0) {
ff_format_io_close(s, &in);
return ret;
}
while (size > 0) {
uint8_t buf[8192];
int n = FFMIN(size, sizeof(buf));
n = avio_read(in, buf, n);
if (n <= 0) {
ret = AVERROR(EIO);
break;
}
avio_write(out, buf, n);
size -= n;
}
avio_flush(out);
ff_format_io_close(s, &out);
ff_format_io_close(s, &in);
return ret;
}
static int ism_flush(AVFormatContext *s, int final)
{
SmoothStreamingContext *c = s->priv_data;
int i, ret = 0;
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
char filename[1024], target_filename[1024], header_filename[1024], curr_dirname[1024];
int64_t size;
int64_t start_ts, duration, moof_size;
if (!os->packets_written)
continue;
snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
ret = ffurl_open_whitelist(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL, s->protocol_whitelist, s->protocol_blacklist, NULL);
if (ret < 0)
break;
os->cur_start_pos = os->tail_pos;
av_write_frame(os->ctx, NULL);
avio_flush(os->ctx->pb);
os->packets_written = 0;
if (!os->out || os->tail_out)
return AVERROR(EIO);
ffurl_closep(&os->out);
size = os->tail_pos - os->cur_start_pos;
if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
break;
if (!s->streams[i]->codecpar->bit_rate) {
int64_t bitrate = (int64_t) size * 8 * AV_TIME_BASE / av_rescale_q(duration, s->streams[i]->time_base, AV_TIME_BASE_Q);
if (!bitrate) {
av_log(s, AV_LOG_ERROR, "calculating bitrate got zero.\n");
ret = AVERROR(EINVAL);
return ret;
}
av_log(s, AV_LOG_DEBUG, "calculated bitrate: %"PRId64"\n", bitrate);
s->streams[i]->codecpar->bit_rate = bitrate;
memcpy(curr_dirname, os->dirname, sizeof(os->dirname));
snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%"PRId64")", s->url, s->streams[i]->codecpar->bit_rate);
snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
// rename the tmp folder back to the correct name since we now have the bitrate
if ((ret = ff_rename((const char*)curr_dirname, os->dirname, s)) < 0)
return ret;
}
snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
copy_moof(s, filename, header_filename, moof_size);
ret = ff_rename(filename, target_filename, s);
if (ret < 0)
break;
add_fragment(os, target_filename, header_filename, start_ts, duration,
os->cur_start_pos, size);
}
if (c->window_size || (final && c->remove_at_exit)) {
for (i = 0; i < s->nb_streams; i++) {
OutputStream *os = &c->streams[i];
int j;
int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
if (final && c->remove_at_exit)
remove = os->nb_fragments;
if (remove > 0) {
for (j = 0; j < remove; j++) {
unlink(os->fragments[j]->file);
unlink(os->fragments[j]->infofile);
av_freep(&os->fragments[j]);
}
os->nb_fragments -= remove;
memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
}
if (final && c->remove_at_exit)
rmdir(os->dirname);
}
}
if (ret >= 0)
ret = write_manifest(s, final);
return ret;
}
static int ism_write_packet(AVFormatContext *s, AVPacket *pkt)
{
SmoothStreamingContext *c = s->priv_data;
AVStream *st = s->streams[pkt->stream_index];
FFStream *const sti = ffstream(st);
OutputStream *os = &c->streams[pkt->stream_index];
int64_t end_dts = (c->nb_fragments + 1) * (int64_t) c->min_frag_duration;
int ret;
if (sti->first_dts == AV_NOPTS_VALUE)
sti->first_dts = pkt->dts;
if ((!c->has_video || st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) &&
av_compare_ts(pkt->dts - sti->first_dts, st->time_base,
end_dts, AV_TIME_BASE_Q) >= 0 &&
pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
if ((ret = ism_flush(s, 0)) < 0)
return ret;
c->nb_fragments++;
}
os->packets_written++;
return ff_write_chained(os->ctx, 0, pkt, s, 0);
}
static int ism_write_trailer(AVFormatContext *s)
{
SmoothStreamingContext *c = s->priv_data;
ism_flush(s, 1);
if (c->remove_at_exit) {
char filename[1024];
snprintf(filename, sizeof(filename), "%s/Manifest", s->url);
unlink(filename);
rmdir(s->url);
}
return 0;
}
#define OFFSET(x) offsetof(SmoothStreamingContext, x)
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
{ "extra_window_size", "number of fragments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
{ "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
{ "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
{ "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },
{ NULL },
};
static const AVClass ism_class = {
.class_name = "smooth streaming muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
const AVOutputFormat ff_smoothstreaming_muxer = {
.name = "smoothstreaming",
.long_name = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
.priv_data_size = sizeof(SmoothStreamingContext),
.audio_codec = AV_CODEC_ID_AAC,
.video_codec = AV_CODEC_ID_H264,
.flags = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
.write_header = ism_write_header,
.write_packet = ism_write_packet,
.write_trailer = ism_write_trailer,
.deinit = ism_free,
.priv_class = &ism_class,
};