/*

  * Tee pseudo-muxer

  * Copyright (c) 2012 Nicolas George
  *
  * 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 "libavutil/avutil.h"
 #include "libavutil/avstring.h"
 #include "libavutil/opt.h"

 #include "internal.h"

 #include "avformat.h"

 #include "avio_internal.h"

 
 #define MAX_SLAVES 16
 

 typedef struct {
     AVFormatContext *avf;
     AVBitStreamFilterContext **bsfs; ///< bitstream filters per stream

 
     /** map from input to output streams indexes,
      * disabled output streams are set to -1 */
     int *stream_map;

 } TeeSlave;
 

 typedef struct TeeContext {
     const AVClass *class;
     unsigned nb_slaves;

     TeeSlave slaves[MAX_SLAVES];

 } TeeContext;
 
 static const char *const slave_delim     = "|";
 static const char *const slave_opt_open  = "[";
 static const char *const slave_opt_close = "]";
 static const char *const slave_opt_delim = ":]"; /* must have the close too */

 static const char *const slave_bsfs_spec_sep = "/";

 static const char *const slave_select_sep = ",";

 
 static const AVClass tee_muxer_class = {
     .class_name = "Tee muxer",
     .item_name  = av_default_item_name,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 static int parse_slave_options(void *log, char *slave,
                                AVDictionary **options, char **filename)
 {
     const char *p;
     char *key, *val;
     int ret;
 
     if (!strspn(slave, slave_opt_open)) {
         *filename = slave;
         return 0;
     }
     p = slave + 1;
     if (strspn(p, slave_opt_close)) {
         *filename = (char *)p + 1;
         return 0;
     }
     while (1) {
         ret = av_opt_get_key_value(&p, "=", slave_opt_delim, 0, &key, &val);
         if (ret < 0) {
             av_log(log, AV_LOG_ERROR, "No option found near \"%s\"\n", p);
             goto fail;
         }
         ret = av_dict_set(options, key, val,
                           AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
         if (ret < 0)
             goto fail;
         if (strspn(p, slave_opt_close))
             break;
         p++;
     }
     *filename = (char *)p + 1;
     return 0;
 
 fail:
     av_dict_free(options);
     return ret;
 }
 

 /**
  * Parse list of bitstream filters and add them to the list of filters
  * pointed to by bsfs.
  *
  * The list must be specified in the form:
  * BSFS ::= BSF[,BSFS]
  */
 static int parse_bsfs(void *log_ctx, const char *bsfs_spec,
                       AVBitStreamFilterContext **bsfs)
 {

     char *bsf_name, *buf, *dup, *saveptr;

     int ret = 0;

     if (!(dup = buf = av_strdup(bsfs_spec)))

         return AVERROR(ENOMEM);
 
     while (bsf_name = av_strtok(buf, ",", &saveptr)) {
         AVBitStreamFilterContext *bsf = av_bitstream_filter_init(bsf_name);
 
         if (!bsf) {
             av_log(log_ctx, AV_LOG_ERROR,
                    "Cannot initialize bitstream filter with name '%s', "
                    "unknown filter or internal error happened\n",
                    bsf_name);
             ret = AVERROR_UNKNOWN;
             goto end;
         }
 
         /* append bsf context to the list of bsf contexts */
         *bsfs = bsf;
         bsfs = &bsf->next;
 
         buf = NULL;
     }
 
 end:

     av_free(dup);

     return ret;
 }
 
 static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)

 {
     int i, ret;
     AVDictionary *options = NULL;
     AVDictionaryEntry *entry;
     char *filename;

     char *format = NULL, *select = NULL;

     AVFormatContext *avf2 = NULL;
     AVStream *st, *st2;

     int stream_count;

     int fullret;
     char *subselect = NULL, *next_subselect = NULL, *first_subselect = NULL, *tmp_select = NULL;

 
     if ((ret = parse_slave_options(avf, slave, &options, &filename)) < 0)
         return ret;

 
 #define STEAL_OPTION(option, field) do {                                \
         if ((entry = av_dict_get(options, option, NULL, 0))) {          \
             field = entry->value;                                       \
             entry->value = NULL; /* prevent it from being freed */      \
             av_dict_set(&options, option, NULL, 0);                     \
         }                                                               \
     } while (0)
 
     STEAL_OPTION("f", format);
     STEAL_OPTION("select", select);

     ret = avformat_alloc_output_context2(&avf2, NULL, format, filename);

     if (ret < 0)

         goto end;

     av_dict_copy(&avf2->metadata, avf->metadata, 0);

     avf2->opaque   = avf->opaque;
     avf2->io_open  = avf->io_open;
     avf2->io_close = avf->io_close;

     tee_slave->stream_map = av_calloc(avf->nb_streams, sizeof(*tee_slave->stream_map));
     if (!tee_slave->stream_map) {
         ret = AVERROR(ENOMEM);
         goto end;
     }
 
     stream_count = 0;

     for (i = 0; i < avf->nb_streams; i++) {
         st = avf->streams[i];

         if (select) {

             tmp_select = av_strdup(select);  // av_strtok is destructive so we regenerate it in each loop
             if (!tmp_select) {
                 ret = AVERROR(ENOMEM);

                 goto end;
             }

             fullret = 0;
             first_subselect = tmp_select;
             next_subselect = NULL;
             while (subselect = av_strtok(first_subselect, slave_select_sep, &next_subselect)) {
                 first_subselect = NULL;
 
                 ret = avformat_match_stream_specifier(avf, avf->streams[i], subselect);
                 if (ret < 0) {
                     av_log(avf, AV_LOG_ERROR,
                            "Invalid stream specifier '%s' for output '%s'\n",
                            subselect, slave);
                     goto end;
                 }
                 if (ret != 0) {
                     fullret = 1; // match
                     break;
                 }
             }
             av_freep(&tmp_select);

             if (fullret == 0) { /* no match */

                 tee_slave->stream_map[i] = -1;
                 continue;
             }
         }
         tee_slave->stream_map[i] = stream_count++;
 

         if (!(st2 = avformat_new_stream(avf2, NULL))) {
             ret = AVERROR(ENOMEM);

             goto end;

         }
         st2->id = st->id;
         st2->r_frame_rate        = st->r_frame_rate;
         st2->time_base           = st->time_base;
         st2->start_time          = st->start_time;
         st2->duration            = st->duration;
         st2->nb_frames           = st->nb_frames;
         st2->disposition         = st->disposition;
         st2->sample_aspect_ratio = st->sample_aspect_ratio;
         st2->avg_frame_rate      = st->avg_frame_rate;
         av_dict_copy(&st2->metadata, st->metadata, 0);
         if ((ret = avcodec_copy_context(st2->codec, st->codec)) < 0)

             goto end;

     }
 
     if (!(avf2->oformat->flags & AVFMT_NOFILE)) {

         if ((ret = avf2->io_open(avf2, &avf2->pb, filename, AVIO_FLAG_WRITE, NULL)) < 0) {

             av_log(avf, AV_LOG_ERROR, "Slave '%s': error opening: %s\n",
                    slave, av_err2str(ret));

             goto end;

         }
     }
 
     if ((ret = avformat_write_header(avf2, &options)) < 0) {
         av_log(avf, AV_LOG_ERROR, "Slave '%s': error writing header: %s\n",
                slave, av_err2str(ret));

         goto end;
     }
 
     tee_slave->avf = avf2;
     tee_slave->bsfs = av_calloc(avf2->nb_streams, sizeof(TeeSlave));
     if (!tee_slave->bsfs) {
         ret = AVERROR(ENOMEM);
         goto end;
     }
 
     entry = NULL;
     while (entry = av_dict_get(options, "bsfs", NULL, AV_DICT_IGNORE_SUFFIX)) {
         const char *spec = entry->key + strlen("bsfs");
         if (*spec) {
             if (strspn(spec, slave_bsfs_spec_sep) != 1) {
                 av_log(avf, AV_LOG_ERROR,
                        "Specifier separator in '%s' is '%c', but only characters '%s' "
                        "are allowed\n", entry->key, *spec, slave_bsfs_spec_sep);
                 return AVERROR(EINVAL);
             }
             spec++; /* consume separator */
         }
 
         for (i = 0; i < avf2->nb_streams; i++) {
             ret = avformat_match_stream_specifier(avf2, avf2->streams[i], spec);
             if (ret < 0) {
                 av_log(avf, AV_LOG_ERROR,
                        "Invalid stream specifier '%s' in bsfs option '%s' for slave "
                        "output '%s'\n", spec, entry->key, filename);
                 goto end;
             }
 
             if (ret > 0) {
                 av_log(avf, AV_LOG_DEBUG, "spec:%s bsfs:%s matches stream %d of slave "
                        "output '%s'\n", spec, entry->value, i, filename);
                 if (tee_slave->bsfs[i]) {
                     av_log(avf, AV_LOG_WARNING,
                            "Duplicate bsfs specification associated to stream %d of slave "
                            "output '%s', filters will be ignored\n", i, filename);
                     continue;
                 }
                 ret = parse_bsfs(avf, entry->value, &tee_slave->bsfs[i]);
                 if (ret < 0) {
                     av_log(avf, AV_LOG_ERROR,
                            "Error parsing bitstream filter sequence '%s' associated to "
                            "stream %d of slave output '%s'\n", entry->value, i, filename);
                     goto end;
                 }
             }
         }
 
         av_dict_set(&options, entry->key, NULL, 0);

     }

     if (options) {
         entry = NULL;
         while ((entry = av_dict_get(options, "", entry, AV_DICT_IGNORE_SUFFIX)))
             av_log(avf2, AV_LOG_ERROR, "Unknown option '%s'\n", entry->key);
         ret = AVERROR_OPTION_NOT_FOUND;

         goto end;

     }
 

 end:
     av_free(format);

     av_free(select);

     av_dict_free(&options);

     av_freep(&tmp_select);

     return ret;
 }
 
 static void close_slaves(AVFormatContext *avf)
 {
     TeeContext *tee = avf->priv_data;
     AVFormatContext *avf2;

     unsigned i, j;

 
     for (i = 0; i < tee->nb_slaves; i++) {

         avf2 = tee->slaves[i].avf;
 
         for (j = 0; j < avf2->nb_streams; j++) {
             AVBitStreamFilterContext *bsf_next, *bsf = tee->slaves[i].bsfs[j];
             while (bsf) {
                 bsf_next = bsf->next;
                 av_bitstream_filter_close(bsf);
                 bsf = bsf_next;
             }
         }

         av_freep(&tee->slaves[i].stream_map);

         av_freep(&tee->slaves[i].bsfs);

         ff_format_io_close(avf2, &avf2->pb);

         avformat_free_context(avf2);

         tee->slaves[i].avf = NULL;
     }
 }
 
 static void log_slave(TeeSlave *slave, void *log_ctx, int log_level)
 {
     int i;
     av_log(log_ctx, log_level, "filename:'%s' format:%s\n",
            slave->avf->filename, slave->avf->oformat->name);
     for (i = 0; i < slave->avf->nb_streams; i++) {
         AVStream *st = slave->avf->streams[i];
         AVBitStreamFilterContext *bsf = slave->bsfs[i];
 
         av_log(log_ctx, log_level, "    stream:%d codec:%s type:%s",
                i, avcodec_get_name(st->codec->codec_id),
                av_get_media_type_string(st->codec->codec_type));
         if (bsf) {
             av_log(log_ctx, log_level, " bsfs:");
             while (bsf) {
                 av_log(log_ctx, log_level, "%s%s",
                        bsf->filter->name, bsf->next ? "," : "");
                 bsf = bsf->next;
             }
         }
         av_log(log_ctx, log_level, "\n");

     }
 }
 
 static int tee_write_header(AVFormatContext *avf)
 {
     TeeContext *tee = avf->priv_data;
     unsigned nb_slaves = 0, i;
     const char *filename = avf->filename;
     char *slaves[MAX_SLAVES];
     int ret;
 
     while (*filename) {
         if (nb_slaves == MAX_SLAVES) {
             av_log(avf, AV_LOG_ERROR, "Maximum %d slave muxers reached.\n",
                    MAX_SLAVES);
             ret = AVERROR_PATCHWELCOME;
             goto fail;
         }
         if (!(slaves[nb_slaves++] = av_get_token(&filename, slave_delim))) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
         if (strspn(filename, slave_delim))
             filename++;
     }
 
     for (i = 0; i < nb_slaves; i++) {
         if ((ret = open_slave(avf, slaves[i], &tee->slaves[i])) < 0)
             goto fail;

         log_slave(&tee->slaves[i], avf, AV_LOG_VERBOSE);

         av_freep(&slaves[i]);
     }
 
     tee->nb_slaves = nb_slaves;

 
     for (i = 0; i < avf->nb_streams; i++) {
         int j, mapped = 0;
         for (j = 0; j < tee->nb_slaves; j++)
             mapped += tee->slaves[j].stream_map[i] >= 0;
         if (!mapped)
             av_log(avf, AV_LOG_WARNING, "Input stream #%d is not mapped "
                    "to any slave.\n", i);
     }

     return 0;
 
 fail:
     for (i = 0; i < nb_slaves; i++)
         av_freep(&slaves[i]);
     close_slaves(avf);
     return ret;
 }
 
 static int tee_write_trailer(AVFormatContext *avf)
 {
     TeeContext *tee = avf->priv_data;
     AVFormatContext *avf2;
     int ret_all = 0, ret;
     unsigned i;
 
     for (i = 0; i < tee->nb_slaves; i++) {

         avf2 = tee->slaves[i].avf;

         if ((ret = av_write_trailer(avf2)) < 0)
             if (!ret_all)
                 ret_all = ret;

         if (!(avf2->oformat->flags & AVFMT_NOFILE))
             ff_format_io_close(avf2, &avf2->pb);

     }
     close_slaves(avf);
     return ret_all;
 }
 
 static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
 {
     TeeContext *tee = avf->priv_data;
     AVFormatContext *avf2;
     AVPacket pkt2;
     int ret_all = 0, ret;
     unsigned i, s;

     int s2;

     AVRational tb, tb2;
 
     for (i = 0; i < tee->nb_slaves; i++) {

         avf2 = tee->slaves[i].avf;

         s = pkt->stream_index;

         s2 = tee->slaves[i].stream_map[s];
         if (s2 < 0)

             continue;

         if ((ret = av_copy_packet(&pkt2, pkt)) < 0 ||
             (ret = av_dup_packet(&pkt2))< 0)
             if (!ret_all) {

                 ret_all = ret;

                 continue;
             }

         tb  = avf ->streams[s ]->time_base;
         tb2 = avf2->streams[s2]->time_base;

         pkt2.pts      = av_rescale_q(pkt->pts,      tb, tb2);
         pkt2.dts      = av_rescale_q(pkt->dts,      tb, tb2);
         pkt2.duration = av_rescale_q(pkt->duration, tb, tb2);

         pkt2.stream_index = s2;

         if ((ret = av_apply_bitstream_filters(avf2->streams[s2]->codec, &pkt2,
                                               tee->slaves[i].bsfs[s2])) < 0 ||
             (ret = av_interleaved_write_frame(avf2, &pkt2)) < 0)

             if (!ret_all)
                 ret_all = ret;
     }
     return ret_all;
 }
 
 AVOutputFormat ff_tee_muxer = {
     .name              = "tee",
     .long_name         = NULL_IF_CONFIG_SMALL("Multiple muxer tee"),
     .priv_data_size    = sizeof(TeeContext),
     .write_header      = tee_write_header,
     .write_trailer     = tee_write_trailer,
     .write_packet      = tee_write_packet,
     .priv_class        = &tee_muxer_class,
     .flags             = AVFMT_NOFILE,
 };