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  1. /*
  2.  * Live smooth streaming fragmenter
  3.  * Copyright (c) 2012 Martin Storsjo
  4.  *
  5.  * This file is part of FFmpeg.
  6.  *
  7.  * FFmpeg is free software; you can redistribute it and/or
  8.  * modify it under the terms of the GNU Lesser General Public
  9.  * License as published by the Free Software Foundation; either
  10.  * version 2.1 of the License, or (at your option) any later version.
  11.  *
  12.  * FFmpeg is distributed in the hope that it will be useful,
  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15.  * Lesser General Public License for more details.
  16.  *
  17.  * You should have received a copy of the GNU Lesser General Public
  18.  * License along with FFmpeg; if not, write to the Free Software
  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20.  */
  21.  
  22. #include "config.h"
  23. #include <float.h>
  24. #if HAVE_UNISTD_H
  25. #include <unistd.h>
  26. #endif
  27.  
  28. #include "avformat.h"
  29. #include "internal.h"
  30. #include "os_support.h"
  31. #include "avc.h"
  32. #include "url.h"
  33. #include "isom.h"
  34.  
  35. #include "libavutil/opt.h"
  36. #include "libavutil/avstring.h"
  37. #include "libavutil/file.h"
  38. #include "libavutil/mathematics.h"
  39. #include "libavutil/intreadwrite.h"
  40.  
  41. typedef struct Fragment {
  42.     char file[1024];
  43.     char infofile[1024];
  44.     int64_t start_time, duration;
  45.     int n;
  46.     int64_t start_pos, size;
  47. } Fragment;
  48.  
  49. typedef struct OutputStream {
  50.     AVFormatContext *ctx;
  51.     int ctx_inited;
  52.     char dirname[1024];
  53.     uint8_t iobuf[32768];
  54.     URLContext *out;  // Current output stream where all output is written
  55.     URLContext *out2; // Auxiliary output stream where all output is also written
  56.     URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
  57.     int64_t tail_pos, cur_pos, cur_start_pos;
  58.     int packets_written;
  59.     const char *stream_type_tag;
  60.     int nb_fragments, fragments_size, fragment_index;
  61.     Fragment **fragments;
  62.  
  63.     const char *fourcc;
  64.     char *private_str;
  65.     int packet_size;
  66.     int audio_tag;
  67. } OutputStream;
  68.  
  69. typedef struct SmoothStreamingContext {
  70.     const AVClass *class;  /* Class for private options. */
  71.     int window_size;
  72.     int extra_window_size;
  73.     int lookahead_count;
  74.     int min_frag_duration;
  75.     int remove_at_exit;
  76.     OutputStream *streams;
  77.     int has_video, has_audio;
  78.     int nb_fragments;
  79. } SmoothStreamingContext;
  80.  
  81. static int ism_write(void *opaque, uint8_t *buf, int buf_size)
  82. {
  83.     OutputStream *os = opaque;
  84.     if (os->out)
  85.         ffurl_write(os->out, buf, buf_size);
  86.     if (os->out2)
  87.         ffurl_write(os->out2, buf, buf_size);
  88.     os->cur_pos += buf_size;
  89.     if (os->cur_pos >= os->tail_pos)
  90.         os->tail_pos = os->cur_pos;
  91.     return buf_size;
  92. }
  93.  
  94. static int64_t ism_seek(void *opaque, int64_t offset, int whence)
  95. {
  96.     OutputStream *os = opaque;
  97.     int i;
  98.     if (whence != SEEK_SET)
  99.         return AVERROR(ENOSYS);
  100.     if (os->tail_out) {
  101.         if (os->out) {
  102.             ffurl_close(os->out);
  103.         }
  104.         if (os->out2) {
  105.             ffurl_close(os->out2);
  106.         }
  107.         os->out = os->tail_out;
  108.         os->out2 = NULL;
  109.         os->tail_out = NULL;
  110.     }
  111.     if (offset >= os->cur_start_pos) {
  112.         if (os->out)
  113.             ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
  114.         os->cur_pos = offset;
  115.         return offset;
  116.     }
  117.     for (i = os->nb_fragments - 1; i >= 0; i--) {
  118.         Fragment *frag = os->fragments[i];
  119.         if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
  120.             int ret;
  121.             AVDictionary *opts = NULL;
  122.             os->tail_out = os->out;
  123.             av_dict_set(&opts, "truncate", "0", 0);
  124.             ret = ffurl_open(&os->out, frag->file, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
  125.             av_dict_free(&opts);
  126.             if (ret < 0) {
  127.                 os->out = os->tail_out;
  128.                 os->tail_out = NULL;
  129.                 return ret;
  130.             }
  131.             av_dict_set(&opts, "truncate", "0", 0);
  132.             ffurl_open(&os->out2, frag->infofile, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
  133.             av_dict_free(&opts);
  134.             ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
  135.             if (os->out2)
  136.                 ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
  137.             os->cur_pos = offset;
  138.             return offset;
  139.         }
  140.     }
  141.     return AVERROR(EIO);
  142. }
  143.  
  144. static void get_private_data(OutputStream *os)
  145. {
  146.     AVCodecContext *codec = os->ctx->streams[0]->codec;
  147.     uint8_t *ptr = codec->extradata;
  148.     int size = codec->extradata_size;
  149.     int i;
  150.     if (codec->codec_id == AV_CODEC_ID_H264) {
  151.         ff_avc_write_annexb_extradata(ptr, &ptr, &size);
  152.         if (!ptr)
  153.             ptr = codec->extradata;
  154.     }
  155.     if (!ptr)
  156.         return;
  157.     os->private_str = av_mallocz(2*size + 1);
  158.     if (!os->private_str)
  159.         goto fail;
  160.     for (i = 0; i < size; i++)
  161.         snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
  162. fail:
  163.     if (ptr != codec->extradata)
  164.         av_free(ptr);
  165. }
  166.  
  167. static void ism_free(AVFormatContext *s)
  168. {
  169.     SmoothStreamingContext *c = s->priv_data;
  170.     int i, j;
  171.     if (!c->streams)
  172.         return;
  173.     for (i = 0; i < s->nb_streams; i++) {
  174.         OutputStream *os = &c->streams[i];
  175.         ffurl_close(os->out);
  176.         ffurl_close(os->out2);
  177.         ffurl_close(os->tail_out);
  178.         os->out = os->out2 = os->tail_out = NULL;
  179.         if (os->ctx && os->ctx_inited)
  180.             av_write_trailer(os->ctx);
  181.         if (os->ctx && os->ctx->pb)
  182.             av_freep(&os->ctx->pb);
  183.         if (os->ctx)
  184.             avformat_free_context(os->ctx);
  185.         av_freep(&os->private_str);
  186.         for (j = 0; j < os->nb_fragments; j++)
  187.             av_freep(&os->fragments[j]);
  188.         av_freep(&os->fragments);
  189.     }
  190.     av_freep(&c->streams);
  191. }
  192.  
  193. static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
  194. {
  195.     int removed = 0, i, start = 0;
  196.     if (os->nb_fragments <= 0)
  197.         return;
  198.     if (os->fragments[0]->n > 0)
  199.         removed = 1;
  200.     if (final)
  201.         skip = 0;
  202.     if (window_size)
  203.         start = FFMAX(os->nb_fragments - skip - window_size, 0);
  204.     for (i = start; i < os->nb_fragments - skip; i++) {
  205.         Fragment *frag = os->fragments[i];
  206.         if (!final || removed)
  207.             avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
  208.         else
  209.             avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
  210.     }
  211. }
  212.  
  213. static int write_manifest(AVFormatContext *s, int final)
  214. {
  215.     SmoothStreamingContext *c = s->priv_data;
  216.     AVIOContext *out;
  217.     char filename[1024], temp_filename[1024];
  218.     int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
  219.     int64_t duration = 0;
  220.  
  221.     snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
  222.     snprintf(temp_filename, sizeof(temp_filename), "%s/Manifest.tmp", s->filename);
  223.     ret = avio_open2(&out, temp_filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
  224.     if (ret < 0) {
  225.         av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
  226.         return ret;
  227.     }
  228.     avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
  229.     for (i = 0; i < s->nb_streams; i++) {
  230.         OutputStream *os = &c->streams[i];
  231.         if (os->nb_fragments > 0) {
  232.             Fragment *last = os->fragments[os->nb_fragments - 1];
  233.             duration = last->start_time + last->duration;
  234.         }
  235.         if (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  236.             video_chunks = os->nb_fragments;
  237.             video_streams++;
  238.         } else {
  239.             audio_chunks = os->nb_fragments;
  240.             audio_streams++;
  241.         }
  242.     }
  243.     if (!final) {
  244.         duration = 0;
  245.         video_chunks = audio_chunks = 0;
  246.     }
  247.     if (c->window_size) {
  248.         video_chunks = FFMIN(video_chunks, c->window_size);
  249.         audio_chunks = FFMIN(audio_chunks, c->window_size);
  250.     }
  251.     avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
  252.     if (!final)
  253.         avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
  254.     avio_printf(out, ">\n");
  255.     if (c->has_video) {
  256.         int last = -1, index = 0;
  257.         avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
  258.         for (i = 0; i < s->nb_streams; i++) {
  259.             OutputStream *os = &c->streams[i];
  260.             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_VIDEO)
  261.                 continue;
  262.             last = i;
  263.             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);
  264.             index++;
  265.         }
  266.         output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
  267.         avio_printf(out, "</StreamIndex>\n");
  268.     }
  269.     if (c->has_audio) {
  270.         int last = -1, index = 0;
  271.         avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
  272.         for (i = 0; i < s->nb_streams; i++) {
  273.             OutputStream *os = &c->streams[i];
  274.             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
  275.                 continue;
  276.             last = i;
  277.             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);
  278.             index++;
  279.         }
  280.         output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
  281.         avio_printf(out, "</StreamIndex>\n");
  282.     }
  283.     avio_printf(out, "</SmoothStreamingMedia>\n");
  284.     avio_flush(out);
  285.     avio_close(out);
  286.     return ff_rename(temp_filename, filename, s);
  287. }
  288.  
  289. static int ism_write_header(AVFormatContext *s)
  290. {
  291.     SmoothStreamingContext *c = s->priv_data;
  292.     int ret = 0, i;
  293.     AVOutputFormat *oformat;
  294.  
  295.     if (mkdir(s->filename, 0777) == -1 && errno != EEXIST) {
  296.         ret = AVERROR(errno);
  297.         av_log(s, AV_LOG_ERROR, "mkdir failed\n");
  298.         goto fail;
  299.     }
  300.  
  301.     oformat = av_guess_format("ismv", NULL, NULL);
  302.     if (!oformat) {
  303.         ret = AVERROR_MUXER_NOT_FOUND;
  304.         goto fail;
  305.     }
  306.  
  307.     c->streams = av_mallocz_array(s->nb_streams, sizeof(*c->streams));
  308.     if (!c->streams) {
  309.         ret = AVERROR(ENOMEM);
  310.         goto fail;
  311.     }
  312.  
  313.     for (i = 0; i < s->nb_streams; i++) {
  314.         OutputStream *os = &c->streams[i];
  315.         AVFormatContext *ctx;
  316.         AVStream *st;
  317.         AVDictionary *opts = NULL;
  318.  
  319.         if (!s->streams[i]->codec->bit_rate) {
  320.             av_log(s, AV_LOG_ERROR, "No bit rate set for stream %d\n", i);
  321.             ret = AVERROR(EINVAL);
  322.             goto fail;
  323.         }
  324.         snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%d)", s->filename, s->streams[i]->codec->bit_rate);
  325.         if (mkdir(os->dirname, 0777) == -1 && errno != EEXIST) {
  326.             ret = AVERROR(errno);
  327.             av_log(s, AV_LOG_ERROR, "mkdir failed\n");
  328.             goto fail;
  329.         }
  330.  
  331.         ctx = avformat_alloc_context();
  332.         if (!ctx) {
  333.             ret = AVERROR(ENOMEM);
  334.             goto fail;
  335.         }
  336.         os->ctx = ctx;
  337.         ctx->oformat = oformat;
  338.         ctx->interrupt_callback = s->interrupt_callback;
  339.  
  340.         if (!(st = avformat_new_stream(ctx, NULL))) {
  341.             ret = AVERROR(ENOMEM);
  342.             goto fail;
  343.         }
  344.         avcodec_copy_context(st->codec, s->streams[i]->codec);
  345.         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
  346.         st->time_base = s->streams[i]->time_base;
  347.  
  348.         ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, ism_write, ism_seek);
  349.         if (!ctx->pb) {
  350.             ret = AVERROR(ENOMEM);
  351.             goto fail;
  352.         }
  353.  
  354.         av_dict_set_int(&opts, "ism_lookahead", c->lookahead_count, 0);
  355.         av_dict_set(&opts, "movflags", "frag_custom", 0);
  356.         if ((ret = avformat_write_header(ctx, &opts)) < 0) {
  357.              goto fail;
  358.         }
  359.         os->ctx_inited = 1;
  360.         avio_flush(ctx->pb);
  361.         av_dict_free(&opts);
  362.         s->streams[i]->time_base = st->time_base;
  363.         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  364.             c->has_video = 1;
  365.             os->stream_type_tag = "video";
  366.             if (st->codec->codec_id == AV_CODEC_ID_H264) {
  367.                 os->fourcc = "H264";
  368.             } else if (st->codec->codec_id == AV_CODEC_ID_VC1) {
  369.                 os->fourcc = "WVC1";
  370.             } else {
  371.                 av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
  372.                 ret = AVERROR(EINVAL);
  373.                 goto fail;
  374.             }
  375.         } else {
  376.             c->has_audio = 1;
  377.             os->stream_type_tag = "audio";
  378.             if (st->codec->codec_id == AV_CODEC_ID_AAC) {
  379.                 os->fourcc = "AACL";
  380.                 os->audio_tag = 0xff;
  381.             } else if (st->codec->codec_id == AV_CODEC_ID_WMAPRO) {
  382.                 os->fourcc = "WMAP";
  383.                 os->audio_tag = 0x0162;
  384.             } else {
  385.                 av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
  386.                 ret = AVERROR(EINVAL);
  387.                 goto fail;
  388.             }
  389.             os->packet_size = st->codec->block_align ? st->codec->block_align : 4;
  390.         }
  391.         get_private_data(os);
  392.     }
  393.  
  394.     if (!c->has_video && c->min_frag_duration <= 0) {
  395.         av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
  396.         ret = AVERROR(EINVAL);
  397.         goto fail;
  398.     }
  399.     ret = write_manifest(s, 0);
  400.  
  401. fail:
  402.     if (ret)
  403.         ism_free(s);
  404.     return ret;
  405. }
  406.  
  407. static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
  408. {
  409.     AVIOContext *in;
  410.     int ret;
  411.     uint32_t len;
  412.     if ((ret = avio_open2(&in, filename, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
  413.         return ret;
  414.     ret = AVERROR(EIO);
  415.     *moof_size = avio_rb32(in);
  416.     if (*moof_size < 8 || *moof_size > size)
  417.         goto fail;
  418.     if (avio_rl32(in) != MKTAG('m','o','o','f'))
  419.         goto fail;
  420.     len = avio_rb32(in);
  421.     if (len > *moof_size)
  422.         goto fail;
  423.     if (avio_rl32(in) != MKTAG('m','f','h','d'))
  424.         goto fail;
  425.     avio_seek(in, len - 8, SEEK_CUR);
  426.     avio_rb32(in); /* traf size */
  427.     if (avio_rl32(in) != MKTAG('t','r','a','f'))
  428.         goto fail;
  429.     while (avio_tell(in) < *moof_size) {
  430.         uint32_t len = avio_rb32(in);
  431.         uint32_t tag = avio_rl32(in);
  432.         int64_t end = avio_tell(in) + len - 8;
  433.         if (len < 8 || len >= *moof_size)
  434.             goto fail;
  435.         if (tag == MKTAG('u','u','i','d')) {
  436.             static const uint8_t tfxd[] = {
  437.                 0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
  438.                 0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
  439.             };
  440.             uint8_t uuid[16];
  441.             avio_read(in, uuid, 16);
  442.             if (!memcmp(uuid, tfxd, 16) && len >= 8 + 16 + 4 + 16) {
  443.                 avio_seek(in, 4, SEEK_CUR);
  444.                 *start_ts = avio_rb64(in);
  445.                 *duration = avio_rb64(in);
  446.                 ret = 0;
  447.                 break;
  448.             }
  449.         }
  450.         avio_seek(in, end, SEEK_SET);
  451.     }
  452. fail:
  453.     avio_close(in);
  454.     return ret;
  455. }
  456.  
  457. 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)
  458. {
  459.     int err;
  460.     Fragment *frag;
  461.     if (os->nb_fragments >= os->fragments_size) {
  462.         os->fragments_size = (os->fragments_size + 1) * 2;
  463.         if ((err = av_reallocp(&os->fragments, sizeof(*os->fragments) *
  464.                                os->fragments_size)) < 0) {
  465.             os->fragments_size = 0;
  466.             os->nb_fragments = 0;
  467.             return err;
  468.         }
  469.     }
  470.     frag = av_mallocz(sizeof(*frag));
  471.     if (!frag)
  472.         return AVERROR(ENOMEM);
  473.     av_strlcpy(frag->file, file, sizeof(frag->file));
  474.     av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
  475.     frag->start_time = start_time;
  476.     frag->duration = duration;
  477.     frag->start_pos = start_pos;
  478.     frag->size = size;
  479.     frag->n = os->fragment_index;
  480.     os->fragments[os->nb_fragments++] = frag;
  481.     os->fragment_index++;
  482.     return 0;
  483. }
  484.  
  485. static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
  486. {
  487.     AVIOContext *in, *out;
  488.     int ret = 0;
  489.     if ((ret = avio_open2(&in, infile, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
  490.         return ret;
  491.     if ((ret = avio_open2(&out, outfile, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL)) < 0) {
  492.         avio_close(in);
  493.         return ret;
  494.     }
  495.     while (size > 0) {
  496.         uint8_t buf[8192];
  497.         int n = FFMIN(size, sizeof(buf));
  498.         n = avio_read(in, buf, n);
  499.         if (n <= 0) {
  500.             ret = AVERROR(EIO);
  501.             break;
  502.         }
  503.         avio_write(out, buf, n);
  504.         size -= n;
  505.     }
  506.     avio_flush(out);
  507.     avio_close(out);
  508.     avio_close(in);
  509.     return ret;
  510. }
  511.  
  512. static int ism_flush(AVFormatContext *s, int final)
  513. {
  514.     SmoothStreamingContext *c = s->priv_data;
  515.     int i, ret = 0;
  516.  
  517.     for (i = 0; i < s->nb_streams; i++) {
  518.         OutputStream *os = &c->streams[i];
  519.         char filename[1024], target_filename[1024], header_filename[1024];
  520.         int64_t size;
  521.         int64_t start_ts, duration, moof_size;
  522.         if (!os->packets_written)
  523.             continue;
  524.  
  525.         snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
  526.         ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
  527.         if (ret < 0)
  528.             break;
  529.         os->cur_start_pos = os->tail_pos;
  530.         av_write_frame(os->ctx, NULL);
  531.         avio_flush(os->ctx->pb);
  532.         os->packets_written = 0;
  533.         if (!os->out || os->tail_out)
  534.             return AVERROR(EIO);
  535.  
  536.         ffurl_close(os->out);
  537.         os->out = NULL;
  538.         size = os->tail_pos - os->cur_start_pos;
  539.         if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
  540.             break;
  541.         snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
  542.         snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
  543.         copy_moof(s, filename, header_filename, moof_size);
  544.         ret = ff_rename(filename, target_filename, s);
  545.         if (ret < 0)
  546.             break;
  547.         add_fragment(os, target_filename, header_filename, start_ts, duration,
  548.                      os->cur_start_pos, size);
  549.     }
  550.  
  551.     if (c->window_size || (final && c->remove_at_exit)) {
  552.         for (i = 0; i < s->nb_streams; i++) {
  553.             OutputStream *os = &c->streams[i];
  554.             int j;
  555.             int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
  556.             if (final && c->remove_at_exit)
  557.                 remove = os->nb_fragments;
  558.             if (remove > 0) {
  559.                 for (j = 0; j < remove; j++) {
  560.                     unlink(os->fragments[j]->file);
  561.                     unlink(os->fragments[j]->infofile);
  562.                     av_freep(&os->fragments[j]);
  563.                 }
  564.                 os->nb_fragments -= remove;
  565.                 memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
  566.             }
  567.             if (final && c->remove_at_exit)
  568.                 rmdir(os->dirname);
  569.         }
  570.     }
  571.  
  572.     if (ret >= 0)
  573.         ret = write_manifest(s, final);
  574.     return ret;
  575. }
  576.  
  577. static int ism_write_packet(AVFormatContext *s, AVPacket *pkt)
  578. {
  579.     SmoothStreamingContext *c = s->priv_data;
  580.     AVStream *st = s->streams[pkt->stream_index];
  581.     OutputStream *os = &c->streams[pkt->stream_index];
  582.     int64_t end_dts = (c->nb_fragments + 1) * (int64_t) c->min_frag_duration;
  583.     int ret;
  584.  
  585.     if (st->first_dts == AV_NOPTS_VALUE)
  586.         st->first_dts = pkt->dts;
  587.  
  588.     if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
  589.         av_compare_ts(pkt->dts - st->first_dts, st->time_base,
  590.                       end_dts, AV_TIME_BASE_Q) >= 0 &&
  591.         pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
  592.  
  593.         if ((ret = ism_flush(s, 0)) < 0)
  594.             return ret;
  595.         c->nb_fragments++;
  596.     }
  597.  
  598.     os->packets_written++;
  599.     return ff_write_chained(os->ctx, 0, pkt, s, 0);
  600. }
  601.  
  602. static int ism_write_trailer(AVFormatContext *s)
  603. {
  604.     SmoothStreamingContext *c = s->priv_data;
  605.     ism_flush(s, 1);
  606.  
  607.     if (c->remove_at_exit) {
  608.         char filename[1024];
  609.         snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
  610.         unlink(filename);
  611.         rmdir(s->filename);
  612.     }
  613.  
  614.     ism_free(s);
  615.     return 0;
  616. }
  617.  
  618. #define OFFSET(x) offsetof(SmoothStreamingContext, x)
  619. #define E AV_OPT_FLAG_ENCODING_PARAM
  620. static const AVOption options[] = {
  621.     { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
  622.     { "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 },
  623.     { "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
  624.     { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
  625.     { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
  626.     { NULL },
  627. };
  628.  
  629. static const AVClass ism_class = {
  630.     .class_name = "smooth streaming muxer",
  631.     .item_name  = av_default_item_name,
  632.     .option     = options,
  633.     .version    = LIBAVUTIL_VERSION_INT,
  634. };
  635.  
  636.  
  637. AVOutputFormat ff_smoothstreaming_muxer = {
  638.     .name           = "smoothstreaming",
  639.     .long_name      = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
  640.     .priv_data_size = sizeof(SmoothStreamingContext),
  641.     .audio_codec    = AV_CODEC_ID_AAC,
  642.     .video_codec    = AV_CODEC_ID_H264,
  643.     .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
  644.     .write_header   = ism_write_header,
  645.     .write_packet   = ism_write_packet,
  646.     .write_trailer  = ism_write_trailer,
  647.     .codec_tag      = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },
  648.     .priv_class     = &ism_class,
  649. };
  650.