FFmpeg: libavformat/smoothstreamingenc.c Source File

00001 /*
00002  * Live smooth streaming fragmenter
00003  * Copyright (c) 2012 Martin Storsjo
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "config.h"
00023 #include <float.h>
00024 #if HAVE_UNISTD_H
00025 #include <unistd.h>
00026 #endif
00027 
00028 #include "avformat.h"
00029 #include "internal.h"
00030 #include "os_support.h"
00031 #include "avc.h"
00032 #include "url.h"
00033 #include "isom.h"
00034 
00035 #include "libavutil/opt.h"
00036 #include "libavutil/avstring.h"
00037 #include "libavutil/mathematics.h"
00038 #include "libavutil/intreadwrite.h"
00039 
00040 typedef struct {
00041     char file[1024];
00042     char infofile[1024];
00043     int64_t start_time, duration;
00044     int n;
00045     int64_t start_pos, size;
00046 } Fragment;
00047 
00048 typedef struct {
00049     AVFormatContext *ctx;
00050     int ctx_inited;
00051     char dirname[1024];
00052     uint8_t iobuf[32768];
00053     URLContext *out;  // Current output stream where all output is written
00054     URLContext *out2; // Auxillary output stream where all output also is written
00055     URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
00056     int64_t tail_pos, cur_pos, cur_start_pos;
00057     int packets_written;
00058     const char *stream_type_tag;
00059     int nb_fragments, fragments_size, fragment_index;
00060     Fragment **fragments;
00061 
00062     const char *fourcc;
00063     char *private_str;
00064     int packet_size;
00065     int audio_tag;
00066 } OutputStream;
00067 
00068 typedef struct {
00069     const AVClass *class;  /* Class for private options. */
00070     int window_size;
00071     int extra_window_size;
00072     int lookahead_count;
00073     int min_frag_duration;
00074     int remove_at_exit;
00075     OutputStream *streams;
00076     int has_video, has_audio;
00077     int nb_fragments;
00078 } SmoothStreamingContext;
00079 
00080 static int ism_write(void *opaque, uint8_t *buf, int buf_size)
00081 {
00082     OutputStream *os = opaque;
00083     if (os->out)
00084         ffurl_write(os->out, buf, buf_size);
00085     if (os->out2)
00086         ffurl_write(os->out2, buf, buf_size);
00087     os->cur_pos += buf_size;
00088     if (os->cur_pos >= os->tail_pos)
00089         os->tail_pos = os->cur_pos;
00090     return buf_size;
00091 }
00092 
00093 static int64_t ism_seek(void *opaque, int64_t offset, int whence)
00094 {
00095     OutputStream *os = opaque;
00096     int i;
00097     if (whence != SEEK_SET)
00098         return AVERROR(ENOSYS);
00099     if (os->tail_out) {
00100         if (os->out) {
00101             ffurl_close(os->out);
00102         }
00103         if (os->out2) {
00104             ffurl_close(os->out2);
00105         }
00106         os->out = os->tail_out;
00107         os->out2 = NULL;
00108         os->tail_out = NULL;
00109     }
00110     if (offset >= os->cur_start_pos) {
00111         if (os->out)
00112             ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
00113         os->cur_pos = offset;
00114         return offset;
00115     }
00116     for (i = os->nb_fragments - 1; i >= 0; i--) {
00117         Fragment *frag = os->fragments[i];
00118         if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
00119             int ret;
00120             AVDictionary *opts = NULL;
00121             os->tail_out = os->out;
00122             av_dict_set(&opts, "truncate", "0", 0);
00123             ret = ffurl_open(&os->out, frag->file, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
00124             av_dict_free(&opts);
00125             if (ret < 0) {
00126                 os->out = os->tail_out;
00127                 os->tail_out = NULL;
00128                 return ret;
00129             }
00130             av_dict_set(&opts, "truncate", "0", 0);
00131             ffurl_open(&os->out2, frag->infofile, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
00132             av_dict_free(&opts);
00133             ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
00134             if (os->out2)
00135                 ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
00136             os->cur_pos = offset;
00137             return offset;
00138         }
00139     }
00140     return AVERROR(EIO);
00141 }
00142 
00143 static void get_private_data(OutputStream *os)
00144 {
00145     AVCodecContext *codec = os->ctx->streams[0]->codec;
00146     uint8_t *ptr = codec->extradata;
00147     int size = codec->extradata_size;
00148     int i;
00149     if (codec->codec_id == AV_CODEC_ID_H264) {
00150         ff_avc_write_annexb_extradata(ptr, &ptr, &size);
00151         if (!ptr)
00152             ptr = codec->extradata;
00153     }
00154     if (!ptr)
00155         return;
00156     os->private_str = av_mallocz(2*size + 1);
00157     for (i = 0; i < size; i++)
00158         snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
00159     if (ptr != codec->extradata)
00160         av_free(ptr);
00161 }
00162 
00163 static void ism_free(AVFormatContext *s)
00164 {
00165     SmoothStreamingContext *c = s->priv_data;
00166     int i, j;
00167     if (!c->streams)
00168         return;
00169     for (i = 0; i < s->nb_streams; i++) {
00170         OutputStream *os = &c->streams[i];
00171         ffurl_close(os->out);
00172         ffurl_close(os->out2);
00173         ffurl_close(os->tail_out);
00174         os->out = os->out2 = os->tail_out = NULL;
00175         if (os->ctx && os->ctx_inited)
00176             av_write_trailer(os->ctx);
00177         if (os->ctx && os->ctx->pb)
00178             av_free(os->ctx->pb);
00179         if (os->ctx)
00180             avformat_free_context(os->ctx);
00181         av_free(os->private_str);
00182         for (j = 0; j < os->nb_fragments; j++)
00183             av_free(os->fragments[j]);
00184         av_free(os->fragments);
00185     }
00186     av_freep(&c->streams);
00187 }
00188 
00189 static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
00190 {
00191     int removed = 0, i, start = 0;
00192     if (os->nb_fragments <= 0)
00193         return;
00194     if (os->fragments[0]->n > 0)
00195         removed = 1;
00196     if (final)
00197         skip = 0;
00198     if (window_size)
00199         start = FFMAX(os->nb_fragments - skip - window_size, 0);
00200     for (i = start; i < os->nb_fragments - skip; i++) {
00201         Fragment *frag = os->fragments[i];
00202         if (!final || removed)
00203             avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
00204         else
00205             avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
00206     }
00207 }
00208 
00209 static int write_manifest(AVFormatContext *s, int final)
00210 {
00211     SmoothStreamingContext *c = s->priv_data;
00212     AVIOContext *out;
00213     char filename[1024];
00214     int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
00215     int64_t duration = 0;
00216 
00217     snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
00218     ret = avio_open2(&out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
00219     if (ret < 0) {
00220         av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", filename);
00221         return ret;
00222     }
00223     avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
00224     for (i = 0; i < s->nb_streams; i++) {
00225         OutputStream *os = &c->streams[i];
00226         if (os->nb_fragments > 0) {
00227             Fragment *last = os->fragments[os->nb_fragments - 1];
00228             duration = last->start_time + last->duration;
00229         }
00230         if (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00231             video_chunks = os->nb_fragments;
00232             video_streams++;
00233         } else {
00234             audio_chunks = os->nb_fragments;
00235             audio_streams++;
00236         }
00237     }
00238     if (!final) {
00239         duration = 0;
00240         video_chunks = audio_chunks = 0;
00241     }
00242     if (c->window_size) {
00243         video_chunks = FFMIN(video_chunks, c->window_size);
00244         audio_chunks = FFMIN(audio_chunks, c->window_size);
00245     }
00246     avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
00247     if (!final)
00248         avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
00249     avio_printf(out, ">\n");
00250     if (c->has_video) {
00251         int last = -1, index = 0;
00252         avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
00253         for (i = 0; i < s->nb_streams; i++) {
00254             OutputStream *os = &c->streams[i];
00255             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_VIDEO)
00256                 continue;
00257             last = i;
00258             avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%d\" FourCC=\"%s\" MaxWidth=\"%d\" MaxHeight=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codec->bit_rate, os->fourcc, s->streams[i]->codec->width, s->streams[i]->codec->height, os->private_str);
00259             index++;
00260         }
00261         output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
00262         avio_printf(out, "</StreamIndex>\n");
00263     }
00264     if (c->has_audio) {
00265         int last = -1, index = 0;
00266         avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
00267         for (i = 0; i < s->nb_streams; i++) {
00268             OutputStream *os = &c->streams[i];
00269             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
00270                 continue;
00271             last = i;
00272             avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%d\" FourCC=\"%s\" SamplingRate=\"%d\" Channels=\"%d\" BitsPerSample=\"16\" PacketSize=\"%d\" AudioTag=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codec->bit_rate, os->fourcc, s->streams[i]->codec->sample_rate, s->streams[i]->codec->channels, os->packet_size, os->audio_tag, os->private_str);
00273             index++;
00274         }
00275         output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
00276         avio_printf(out, "</StreamIndex>\n");
00277     }
00278     avio_printf(out, "</SmoothStreamingMedia>\n");
00279     avio_flush(out);
00280     avio_close(out);
00281     return 0;
00282 }
00283 
00284 static int ism_write_header(AVFormatContext *s)
00285 {
00286     SmoothStreamingContext *c = s->priv_data;
00287     int ret = 0, i;
00288     AVOutputFormat *oformat;
00289 
00290     if (mkdir(s->filename, 0777) < 0) {
00291         av_log(s, AV_LOG_ERROR, "mkdir failed\n");
00292         ret = AVERROR(errno);
00293         goto fail;
00294     }
00295 
00296     oformat = av_guess_format("ismv", NULL, NULL);
00297     if (!oformat) {
00298         ret = AVERROR_MUXER_NOT_FOUND;
00299         goto fail;
00300     }
00301 
00302     c->streams = av_mallocz(sizeof(*c->streams) * s->nb_streams);
00303     if (!c->streams) {
00304         ret = AVERROR(ENOMEM);
00305         goto fail;
00306     }
00307 
00308     for (i = 0; i < s->nb_streams; i++) {
00309         OutputStream *os = &c->streams[i];
00310         AVFormatContext *ctx;
00311         AVStream *st;
00312         AVDictionary *opts = NULL;
00313         char buf[10];
00314 
00315         if (!s->streams[i]->codec->bit_rate) {
00316             av_log(s, AV_LOG_ERROR, "No bit rate set for stream %d\n", i);
00317             ret = AVERROR(EINVAL);
00318             goto fail;
00319         }
00320         snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%d)", s->filename, s->streams[i]->codec->bit_rate);
00321         if (mkdir(os->dirname, 0777) < 0) {
00322             ret = AVERROR(errno);
00323             av_log(s, AV_LOG_ERROR, "mkdir failed\n");
00324             goto fail;
00325         }
00326 
00327         ctx = avformat_alloc_context();
00328         if (!ctx) {
00329             ret = AVERROR(ENOMEM);
00330             goto fail;
00331         }
00332         os->ctx = ctx;
00333         ctx->oformat = oformat;
00334         ctx->interrupt_callback = s->interrupt_callback;
00335 
00336         if (!(st = avformat_new_stream(ctx, NULL))) {
00337             ret = AVERROR(ENOMEM);
00338             goto fail;
00339         }
00340         avcodec_copy_context(st->codec, s->streams[i]->codec);
00341         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
00342 
00343         ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, ism_write, ism_seek);
00344         if (!ctx->pb) {
00345             ret = AVERROR(ENOMEM);
00346             goto fail;
00347         }
00348 
00349         snprintf(buf, sizeof(buf), "%d", c->lookahead_count);
00350         av_dict_set(&opts, "ism_lookahead", buf, 0);
00351         av_dict_set(&opts, "movflags", "frag_custom", 0);
00352         if ((ret = avformat_write_header(ctx, &opts)) < 0) {
00353              goto fail;
00354         }
00355         os->ctx_inited = 1;
00356         avio_flush(ctx->pb);
00357         av_dict_free(&opts);
00358         s->streams[i]->time_base = st->time_base;
00359         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00360             c->has_video = 1;
00361             os->stream_type_tag = "video";
00362             if (st->codec->codec_id == AV_CODEC_ID_H264) {
00363                 os->fourcc = "H264";
00364             } else if (st->codec->codec_id == AV_CODEC_ID_VC1) {
00365                 os->fourcc = "WVC1";
00366             } else {
00367                 av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
00368                 ret = AVERROR(EINVAL);
00369                 goto fail;
00370             }
00371         } else {
00372             c->has_audio = 1;
00373             os->stream_type_tag = "audio";
00374             if (st->codec->codec_id == AV_CODEC_ID_AAC) {
00375                 os->fourcc = "AACL";
00376                 os->audio_tag = 0xff;
00377             } else if (st->codec->codec_id == AV_CODEC_ID_WMAPRO) {
00378                 os->fourcc = "WMAP";
00379                 os->audio_tag = 0x0162;
00380             } else {
00381                 av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
00382                 ret = AVERROR(EINVAL);
00383                 goto fail;
00384             }
00385             os->packet_size = st->codec->block_align ? st->codec->block_align : 4;
00386         }
00387         get_private_data(os);
00388     }
00389 
00390     if (!c->has_video && c->min_frag_duration <= 0) {
00391         av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
00392         ret = AVERROR(EINVAL);
00393     }
00394     ret = write_manifest(s, 0);
00395 
00396 fail:
00397     if (ret)
00398         ism_free(s);
00399     return ret;
00400 }
00401 
00402 static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
00403 {
00404     AVIOContext *in;
00405     int ret;
00406     uint32_t len;
00407     if ((ret = avio_open2(&in, filename, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
00408         return ret;
00409     ret = AVERROR(EIO);
00410     *moof_size = avio_rb32(in);
00411     if (*moof_size < 8 || *moof_size > size)
00412         goto fail;
00413     if (avio_rl32(in) != MKTAG('m','o','o','f'))
00414         goto fail;
00415     len = avio_rb32(in);
00416     if (len > *moof_size)
00417         goto fail;
00418     if (avio_rl32(in) != MKTAG('m','f','h','d'))
00419         goto fail;
00420     avio_seek(in, len - 8, SEEK_CUR);
00421     avio_rb32(in); /* traf size */
00422     if (avio_rl32(in) != MKTAG('t','r','a','f'))
00423         goto fail;
00424     while (avio_tell(in) < *moof_size) {
00425         uint32_t len = avio_rb32(in);
00426         uint32_t tag = avio_rl32(in);
00427         int64_t end = avio_tell(in) + len - 8;
00428         if (len < 8 || len >= *moof_size)
00429             goto fail;
00430         if (tag == MKTAG('u','u','i','d')) {
00431             const uint8_t tfxd[] = {
00432                 0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
00433                 0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
00434             };
00435             uint8_t uuid[16];
00436             avio_read(in, uuid, 16);
00437             if (!memcmp(uuid, tfxd, 16) && len >= 8 + 16 + 4 + 16) {
00438                 avio_seek(in, 4, SEEK_CUR);
00439                 *start_ts = avio_rb64(in);
00440                 *duration = avio_rb64(in);
00441                 ret = 0;
00442                 break;
00443             }
00444         }
00445         avio_seek(in, end, SEEK_SET);
00446     }
00447 fail:
00448     avio_close(in);
00449     return ret;
00450 }
00451 
00452 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)
00453 {
00454     Fragment *frag;
00455     if (os->nb_fragments >= os->fragments_size) {
00456         os->fragments_size = (os->fragments_size + 1) * 2;
00457         os->fragments = av_realloc(os->fragments, sizeof(*os->fragments)*os->fragments_size);
00458         if (!os->fragments)
00459             return AVERROR(ENOMEM);
00460     }
00461     frag = av_mallocz(sizeof(*frag));
00462     if (!frag)
00463         return AVERROR(ENOMEM);
00464     av_strlcpy(frag->file, file, sizeof(frag->file));
00465     av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
00466     frag->start_time = start_time;
00467     frag->duration = duration;
00468     frag->start_pos = start_pos;
00469     frag->size = size;
00470     frag->n = os->fragment_index;
00471     os->fragments[os->nb_fragments++] = frag;
00472     os->fragment_index++;
00473     return 0;
00474 }
00475 
00476 static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
00477 {
00478     AVIOContext *in, *out;
00479     int ret = 0;
00480     if ((ret = avio_open2(&in, infile, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
00481         return ret;
00482     if ((ret = avio_open2(&out, outfile, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL)) < 0) {
00483         avio_close(in);
00484         return ret;
00485     }
00486     while (size > 0) {
00487         uint8_t buf[8192];
00488         int n = FFMIN(size, sizeof(buf));
00489         n = avio_read(in, buf, n);
00490         if (n <= 0) {
00491             ret = AVERROR(EIO);
00492             break;
00493         }
00494         avio_write(out, buf, n);
00495         size -= n;
00496     }
00497     avio_flush(out);
00498     avio_close(out);
00499     avio_close(in);
00500     return ret;
00501 }
00502 
00503 static int ism_flush(AVFormatContext *s, int final)
00504 {
00505     SmoothStreamingContext *c = s->priv_data;
00506     int i, ret = 0;
00507 
00508     for (i = 0; i < s->nb_streams; i++) {
00509         OutputStream *os = &c->streams[i];
00510         char filename[1024], target_filename[1024], header_filename[1024];
00511         int64_t start_pos = os->tail_pos, size;
00512         int64_t start_ts, duration, moof_size;
00513         if (!os->packets_written)
00514             continue;
00515 
00516         snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
00517         ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
00518         if (ret < 0)
00519             break;
00520         os->cur_start_pos = os->tail_pos;
00521         av_write_frame(os->ctx, NULL);
00522         avio_flush(os->ctx->pb);
00523         os->packets_written = 0;
00524         if (!os->out || os->tail_out)
00525             return AVERROR(EIO);
00526 
00527         ffurl_close(os->out);
00528         os->out = NULL;
00529         size = os->tail_pos - start_pos;
00530         if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
00531             break;
00532         snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
00533         snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
00534         copy_moof(s, filename, header_filename, moof_size);
00535         rename(filename, target_filename);
00536         add_fragment(os, target_filename, header_filename, start_ts, duration, start_pos, size);
00537     }
00538 
00539     if (c->window_size || (final && c->remove_at_exit)) {
00540         for (i = 0; i < s->nb_streams; i++) {
00541             OutputStream *os = &c->streams[i];
00542             int j;
00543             int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
00544             if (final && c->remove_at_exit)
00545                 remove = os->nb_fragments;
00546             if (remove > 0) {
00547                 for (j = 0; j < remove; j++) {
00548                     unlink(os->fragments[j]->file);
00549                     unlink(os->fragments[j]->infofile);
00550                     av_free(os->fragments[j]);
00551                 }
00552                 os->nb_fragments -= remove;
00553                 memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
00554             }
00555             if (final && c->remove_at_exit)
00556                 rmdir(os->dirname);
00557         }
00558     }
00559 
00560     if (ret >= 0)
00561         ret = write_manifest(s, final);
00562     return ret;
00563 }
00564 
00565 static int ism_write_packet(AVFormatContext *s, AVPacket *pkt)
00566 {
00567     SmoothStreamingContext *c = s->priv_data;
00568     AVStream *st = s->streams[pkt->stream_index];
00569     OutputStream *os = &c->streams[pkt->stream_index];
00570     int64_t end_dts = (c->nb_fragments + 1LL) * c->min_frag_duration;
00571     int ret;
00572 
00573     if (st->first_dts == AV_NOPTS_VALUE)
00574         st->first_dts = pkt->dts;
00575 
00576     if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
00577         av_compare_ts(pkt->dts - st->first_dts, st->time_base,
00578                       end_dts, AV_TIME_BASE_Q) >= 0 &&
00579         pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
00580 
00581         if ((ret = ism_flush(s, 0)) < 0)
00582             return ret;
00583         c->nb_fragments++;
00584     }
00585 
00586     os->packets_written++;
00587     return ff_write_chained(os->ctx, 0, pkt, s);
00588 }
00589 
00590 static int ism_write_trailer(AVFormatContext *s)
00591 {
00592     SmoothStreamingContext *c = s->priv_data;
00593     ism_flush(s, 1);
00594 
00595     if (c->remove_at_exit) {
00596         char filename[1024];
00597         snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
00598         unlink(filename);
00599         rmdir(s->filename);
00600     }
00601 
00602     ism_free(s);
00603     return 0;
00604 }
00605 
00606 #define OFFSET(x) offsetof(SmoothStreamingContext, x)
00607 #define E AV_OPT_FLAG_ENCODING_PARAM
00608 static const AVOption options[] = {
00609     { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
00610     { "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 },
00611     { "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
00612     { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
00613     { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
00614     { NULL },
00615 };
00616 
00617 static const AVClass ism_class = {
00618     .class_name = "smooth streaming muxer",
00619     .item_name  = av_default_item_name,
00620     .option     = options,
00621     .version    = LIBAVUTIL_VERSION_INT,
00622 };
00623 
00624 
00625 AVOutputFormat ff_smoothstreaming_muxer = {
00626     .name           = "smoothstreaming",
00627     .long_name      = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
00628     .priv_data_size = sizeof(SmoothStreamingContext),
00629     .audio_codec    = AV_CODEC_ID_AAC,
00630     .video_codec    = AV_CODEC_ID_H264,
00631     .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
00632     .write_header   = ism_write_header,
00633     .write_packet   = ism_write_packet,
00634     .write_trailer  = ism_write_trailer,
00635     .codec_tag      = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },
00636     .priv_class     = &ism_class,
00637 };