/*
  * FFM (ffserver live feed) muxer

  * Copyright (c) 2001 Fabrice Bellard

  *
  * 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/intreadwrite.h"

 #include "libavutil/intfloat.h"

 #include "libavutil/avassert.h"

 #include "libavutil/parseutils.h"

 #include "libavutil/opt.h"

 #include "avformat.h"

 #include "avio_internal.h"

 #include "internal.h"

 #include "ffm.h"
 
 static void flush_packet(AVFormatContext *s)
 {
     FFMContext *ffm = s->priv_data;
     int fill_size, h;

     AVIOContext *pb = s->pb;

 
     fill_size = ffm->packet_end - ffm->packet_ptr;
     memset(ffm->packet_ptr, 0, fill_size);
 

     av_assert1(avio_tell(pb) % ffm->packet_size == 0);

 
     /* put header */

     avio_wb16(pb, PACKET_ID);
     avio_wb16(pb, fill_size);
     avio_wb64(pb, ffm->dts);

     h = ffm->frame_offset;
     if (ffm->first_packet)
         h |= 0x8000;

     avio_wb16(pb, h);
     avio_write(pb, ffm->packet, ffm->packet_end - ffm->packet);

     avio_flush(pb);

 
     /* prepare next packet */
     ffm->frame_offset = 0; /* no key frame */
     ffm->packet_ptr = ffm->packet;
     ffm->first_packet = 0;
 }
 
 /* 'first' is true if first data of a frame */
 static void ffm_write_data(AVFormatContext *s,
                            const uint8_t *buf, int size,

                            int64_t dts, int header)

 {
     FFMContext *ffm = s->priv_data;
     int len;
 

     if (header && ffm->frame_offset == 0) {

         ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;

         ffm->dts = dts;

     }

 
     /* write as many packets as needed */
     while (size > 0) {
         len = ffm->packet_end - ffm->packet_ptr;
         if (len > size)
             len = size;
         memcpy(ffm->packet_ptr, buf, len);
 
         ffm->packet_ptr += len;
         buf += len;
         size -= len;

         if (ffm->packet_ptr >= ffm->packet_end)

             flush_packet(s);
     }
 }
 

 static void write_header_chunk(AVIOContext *pb, AVIOContext *dpb, unsigned id)
 {
     uint8_t *dyn_buf;
     int dyn_size= avio_close_dyn_buf(dpb, &dyn_buf);
     avio_wb32(pb, id);
     avio_wb32(pb, dyn_size);
     avio_write(pb, dyn_buf, dyn_size);
     av_free(dyn_buf);
 }
 

 static int ffm_write_header_codec_private_ctx(AVFormatContext *s, AVCodecContext *ctx, int type)

 {

     AVIOContext *pb = s->pb;

     AVIOContext *tmp;
     char *buf = NULL;
     int ret;
     const AVCodec *enc = ctx->codec ? ctx->codec : avcodec_find_encoder(ctx->codec_id);
 

     if (!enc) {
         av_log(s, AV_LOG_WARNING, "Stream codec is not found. Codec private options are not stored.\n");
         return 0;
     }

     if (ctx->priv_data && enc->priv_class && enc->priv_data_size) {
         if ((ret = av_opt_serialize(ctx->priv_data, AV_OPT_FLAG_ENCODING_PARAM | type,
                                     AV_OPT_SERIALIZE_SKIP_DEFAULTS, &buf, '=', ',')) < 0)
             return ret;
         if (buf && strlen(buf)) {
             if (avio_open_dyn_buf(&tmp) < 0) {
                 av_free(buf);
                 return AVERROR(ENOMEM);
             }
             avio_put_str(tmp, buf);
             write_header_chunk(pb, tmp, MKBETAG('C', 'P', 'R', 'V'));
         }
         av_free(buf);
     }
     return 0;
 }
 

 static int ffm_write_header_codec_ctx(AVIOContext *pb, AVCodecContext *ctx, unsigned tag, int type)
 {
     AVIOContext *tmp;
     char *buf = NULL;
     int ret, need_coma = 0;
 
 #define SKIP_DEFAULTS   AV_OPT_SERIALIZE_SKIP_DEFAULTS
 #define OPT_FLAGS_EXACT AV_OPT_SERIALIZE_OPT_FLAGS_EXACT
 #define ENC             AV_OPT_FLAG_ENCODING_PARAM
 
     if (avio_open_dyn_buf(&tmp) < 0)
         return AVERROR(ENOMEM);
     if ((ret = av_opt_serialize(ctx, ENC | type, SKIP_DEFAULTS, &buf, '=', ',')) < 0)
         goto fail;
     if (buf && strlen(buf)) {
         avio_write(tmp, buf, strlen(buf));

         av_freep(&buf);

         need_coma = 1;
     }
     if ((ret = av_opt_serialize(ctx, 0, SKIP_DEFAULTS | OPT_FLAGS_EXACT, &buf, '=', ',')) < 0)
         goto fail;
     if (buf && strlen(buf)) {
         if (need_coma)
             avio_w8(tmp, ',');
         avio_write(tmp, buf, strlen(buf));
     }

     av_freep(&buf);

     avio_w8(tmp, 0);
     write_header_chunk(pb, tmp, tag);
     return 0;
   fail:
     av_free(buf);

     ffio_free_dyn_buf(&tmp);

     return ret;
 
 #undef SKIP_DEFAULTS
 #undef OPT_FLAGS_EXACT
 #undef ENC
 }
 

 static int ffm_write_recommended_config(AVIOContext *pb, AVCodecContext *ctx, unsigned tag,
                                         const char *configuration)
 {
     int ret;
     const AVCodec *enc = ctx->codec ? ctx->codec : avcodec_find_encoder(ctx->codec_id);
     AVIOContext *tmp;
     AVDictionaryEntry *t = NULL;
     AVDictionary *all = NULL, *comm = NULL, *prv = NULL;
     char *buf = NULL;
 
     if (!enc || !enc->priv_class || !enc->priv_data_size) {
         /* codec is not known/has no private options, so save everything as common options */
         if (avio_open_dyn_buf(&tmp) < 0)
             return AVERROR(ENOMEM);
         avio_put_str(tmp, configuration);
         write_header_chunk(pb, tmp, tag);
         return 0;
     }
 
     if ((ret = av_dict_parse_string(&all, configuration, "=", ",", 0)) < 0)
         return ret;
 
     while ((t = av_dict_get(all, "", t, AV_DICT_IGNORE_SUFFIX))) {
         if (av_opt_find((void *)&enc->priv_class, t->key, NULL, 0, AV_OPT_SEARCH_FAKE_OBJ)) {
             if ((ret = av_dict_set(&prv, t->key, t->value, 0)) < 0)
                 goto fail;
         } else if ((ret = av_dict_set(&comm, t->key, t->value, 0)) < 0)
             goto fail;
     }
 
     if (comm) {
         if ((ret = av_dict_get_string(comm, &buf, '=', ',')) < 0 ||
             (ret = avio_open_dyn_buf(&tmp)) < 0)
             goto fail;
         avio_put_str(tmp, buf);
         av_freep(&buf);
         write_header_chunk(pb, tmp, tag);
     }
     if (prv) {
         if ((ret = av_dict_get_string(prv, &buf, '=', ',')) < 0 ||
             (ret = avio_open_dyn_buf(&tmp)) < 0)
             goto fail;
         avio_put_str(tmp, buf);
         write_header_chunk(pb, tmp, MKBETAG('C', 'P', 'R', 'V'));
     }
 
   fail:
     av_free(buf);
     av_dict_free(&all);
     av_dict_free(&comm);
     av_dict_free(&prv);
     return ret;
 }
 

 static int ffm_write_header(AVFormatContext *s)
 {
     FFMContext *ffm = s->priv_data;
     AVStream *st;

     AVIOContext *pb = s->pb;

     AVCodecContext *codec;

     int bit_rate, i, ret;

     if ((ret = ff_parse_creation_time_metadata(s, &ffm->start_time, 0)) < 0)
         return ret;

     ffm->packet_size = FFM_PACKET_SIZE;
 
     /* header */

     avio_wl32(pb, MKTAG('F', 'F', 'M', '2'));

     avio_wb32(pb, ffm->packet_size);
     avio_wb64(pb, 0); /* current write position */

     if(avio_open_dyn_buf(&pb) < 0)
         return AVERROR(ENOMEM);
 

     avio_wb32(pb, s->nb_streams);

     bit_rate = 0;
     for(i=0;i<s->nb_streams;i++) {
         st = s->streams[i];
         bit_rate += st->codec->bit_rate;
     }

     avio_wb32(pb, bit_rate);

     write_header_chunk(s->pb, pb, MKBETAG('M', 'A', 'I', 'N'));
 

     /* list of streams */
     for(i=0;i<s->nb_streams;i++) {
         st = s->streams[i];

         avpriv_set_pts_info(st, 64, 1, 1000000);

         if(avio_open_dyn_buf(&pb) < 0)
             return AVERROR(ENOMEM);

 
         codec = st->codec;
         /* generic info */

         avio_wb32(pb, codec->codec_id);
         avio_w8(pb, codec->codec_type);
         avio_wb32(pb, codec->bit_rate);
         avio_wb32(pb, codec->flags);
         avio_wb32(pb, codec->flags2);
         avio_wb32(pb, codec->debug);

         if (codec->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {

             avio_wb32(pb, codec->extradata_size);
             avio_write(pb, codec->extradata, codec->extradata_size);
         }
         write_header_chunk(s->pb, pb, MKBETAG('C', 'O', 'M', 'M'));

         /* specific info */
         switch(codec->codec_type) {

         case AVMEDIA_TYPE_VIDEO:

             if (st->recommended_encoder_configuration) {
                 av_log(NULL, AV_LOG_DEBUG, "writing recommended configuration: %s\n",
                        st->recommended_encoder_configuration);
                 if ((ret = ffm_write_recommended_config(s->pb, codec, MKBETAG('S', '2', 'V', 'I'),
                                                         st->recommended_encoder_configuration)) < 0)
                 return ret;
             } else if ((ret = ffm_write_header_codec_ctx(s->pb, codec, MKBETAG('S', '2', 'V', 'I'), AV_OPT_FLAG_VIDEO_PARAM)) < 0 ||

                        (ret = ffm_write_header_codec_private_ctx(s, codec, AV_OPT_FLAG_VIDEO_PARAM)) < 0)

                 return ret;

             break;

         case AVMEDIA_TYPE_AUDIO:

             if (st->recommended_encoder_configuration) {
                 av_log(NULL, AV_LOG_DEBUG, "writing recommended configuration: %s\n",
                        st->recommended_encoder_configuration);
                 if ((ret = ffm_write_recommended_config(s->pb, codec, MKBETAG('S', '2', 'A', 'U'),
                                                         st->recommended_encoder_configuration)) < 0)
                 return ret;
             } else if ((ret = ffm_write_header_codec_ctx(s->pb, codec, MKBETAG('S', '2', 'A', 'U'), AV_OPT_FLAG_AUDIO_PARAM)) < 0 ||

                      (ret = ffm_write_header_codec_private_ctx(s, codec, AV_OPT_FLAG_AUDIO_PARAM)) < 0)

                 return ret;

             break;
         default:
             return -1;
         }
     }

     pb = s->pb;
 
     avio_wb64(pb, 0); // end of header

 
     /* flush until end of block reached */

     while ((avio_tell(pb) % ffm->packet_size) != 0)

         avio_w8(pb, 0);

     avio_flush(pb);

 
     /* init packet mux */
     ffm->packet_ptr = ffm->packet;
     ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;

     av_assert0(ffm->packet_end >= ffm->packet);

     ffm->frame_offset = 0;

     ffm->dts = 0;

     ffm->first_packet = 1;
 
     return 0;
 }
 
 static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
 {

     FFMContext *ffm = s->priv_data;

     int64_t dts;

     uint8_t header[FRAME_HEADER_SIZE+4];

     int header_size = FRAME_HEADER_SIZE;

     dts = ffm->start_time + pkt->dts;

     /* packet size & key_frame */
     header[0] = pkt->stream_index;
     header[1] = 0;

     if (pkt->flags & AV_PKT_FLAG_KEY)

         header[1] |= FLAG_KEY_FRAME;
     AV_WB24(header+2, pkt->size);
     AV_WB24(header+5, pkt->duration);

     AV_WB64(header+8, ffm->start_time + pkt->pts);

     if (pkt->pts != pkt->dts) {
         header[1] |= FLAG_DTS;
         AV_WB32(header+16, pkt->pts - pkt->dts);
         header_size += 4;
     }

     ffm_write_data(s, header, header_size, dts, 1);
     ffm_write_data(s, pkt->data, pkt->size, dts, 0);

 
     return 0;
 }
 
 static int ffm_write_trailer(AVFormatContext *s)
 {
     FFMContext *ffm = s->priv_data;
 
     /* flush packets */
     if (ffm->packet_ptr > ffm->packet)
         flush_packet(s);
 
     return 0;
 }
 

 AVOutputFormat ff_ffm_muxer = {

     .name              = "ffm",

     .long_name         = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),

     .extensions        = "ffm",
     .priv_data_size    = sizeof(FFMContext),

     .audio_codec       = AV_CODEC_ID_MP2,
     .video_codec       = AV_CODEC_ID_MPEG1VIDEO,

     .write_header      = ffm_write_header,
     .write_packet      = ffm_write_packet,
     .write_trailer     = ffm_write_trailer,

     .flags             = AVFMT_TS_NEGATIVE,

 };