/*

  * Yamaha SMAF format
  * Copyright (c) 2005 Vidar Madsen
  *

  * 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 "avformat.h"

 #include "raw.h"

 #include "riff.h"

 
 typedef struct {

     int64_t atrpos, atsqpos, awapos;
     int64_t data_size;

 } MMFContext;
 

 static const int mmf_rates[] = { 4000, 8000, 11025, 22050, 44100 };

 static int mmf_rate(int code)
 {
     if((code < 0) || (code > 4))
         return -1;
     return mmf_rates[code];
 }
 

 #if CONFIG_MMF_MUXER

 static int mmf_rate_code(int rate)
 {
     int i;
     for(i = 0; i < 5; i++)
         if(mmf_rates[i] == rate)
             return i;
     return -1;
 }
 
 /* Copy of end_tag() from avienc.c, but for big-endian chunk size */

 static void end_tag_be(ByteIOContext *pb, int64_t start)

 {

     int64_t pos;

 
     pos = url_ftell(pb);
     url_fseek(pb, start - 4, SEEK_SET);
     put_be32(pb, (uint32_t)(pos - start));
     url_fseek(pb, pos, SEEK_SET);
 }
 
 static int mmf_write_header(AVFormatContext *s)
 {
     MMFContext *mmf = s->priv_data;

     ByteIOContext *pb = s->pb;

     int64_t pos;

     int rate;
 

     rate = mmf_rate_code(s->streams[0]->codec->sample_rate);

     if(rate < 0) {

         av_log(s, AV_LOG_ERROR, "Unsupported sample rate %d\n", s->streams[0]->codec->sample_rate);

         return -1;
     }

     put_tag(pb, "MMMD");
     put_be32(pb, 0);
     pos = start_tag(pb, "CNTI");
     put_byte(pb, 0); /* class */
     put_byte(pb, 0); /* type */
     put_byte(pb, 0); /* code type */
     put_byte(pb, 0); /* status */
     put_byte(pb, 0); /* counts */
     put_tag(pb, "VN:libavcodec,"); /* metadata ("ST:songtitle,VN:version,...") */
     end_tag_be(pb, pos);
 
     put_buffer(pb, "ATR\x00", 4);
     put_be32(pb, 0);
     mmf->atrpos = url_ftell(pb);
     put_byte(pb, 0); /* format type */
     put_byte(pb, 0); /* sequence type */
     put_byte(pb, (0 << 7) | (1 << 4) | rate); /* (channel << 7) | (format << 4) | rate */
     put_byte(pb, 0); /* wave base bit */
     put_byte(pb, 2); /* time base d */
     put_byte(pb, 2); /* time base g */
 
     put_tag(pb, "Atsq");
     put_be32(pb, 16);
     mmf->atsqpos = url_ftell(pb);
     /* Will be filled on close */
     put_buffer(pb, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16);
 
     mmf->awapos = start_tag(pb, "Awa\x01");
 

     av_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);

 
     put_flush_packet(pb);
 
     return 0;
 }
 
 static int mmf_write_packet(AVFormatContext *s, AVPacket *pkt)
 {

     ByteIOContext *pb = s->pb;

     put_buffer(pb, pkt->data, pkt->size);
     return 0;
 }
 
 /* Write a variable-length symbol */
 static void put_varlength(ByteIOContext *pb, int val)
 {
     if(val < 128)
         put_byte(pb, val);
     else {
         val -= 128;
         put_byte(pb, 0x80 | val >> 7);
         put_byte(pb, 0x7f & val);
     }
 }
 
 static int mmf_write_trailer(AVFormatContext *s)
 {

     ByteIOContext *pb = s->pb;

     MMFContext *mmf = s->priv_data;

     int64_t pos, size;

     int gatetime;
 

     if (!url_is_streamed(s->pb)) {

         /* Fill in length fields */
         end_tag_be(pb, mmf->awapos);
         end_tag_be(pb, mmf->atrpos);
         end_tag_be(pb, 8);
 
         pos = url_ftell(pb);
         size = pos - mmf->awapos;
 
         /* Fill Atsq chunk */
         url_fseek(pb, mmf->atsqpos, SEEK_SET);
 
         /* "play wav" */
         put_byte(pb, 0); /* start time */
         put_byte(pb, 1); /* (channel << 6) | wavenum */

         gatetime = size * 500 / s->streams[0]->codec->sample_rate;

         put_varlength(pb, gatetime); /* duration */
 
         /* "nop" */
         put_varlength(pb, gatetime); /* start time */
         put_buffer(pb, "\xff\x00", 2); /* nop */
 
         /* "end of sequence" */
         put_buffer(pb, "\x00\x00\x00\x00", 4);
 
         url_fseek(pb, pos, SEEK_SET);
 
         put_flush_packet(pb);
     }
     return 0;
 }

 #endif /* CONFIG_MMF_MUXER */

 
 static int mmf_probe(AVProbeData *p)
 {
     /* check file header */
     if (p->buf[0] == 'M' && p->buf[1] == 'M' &&
         p->buf[2] == 'M' && p->buf[3] == 'D' &&
         p->buf[8] == 'C' && p->buf[9] == 'N' &&
         p->buf[10] == 'T' && p->buf[11] == 'I')
         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 
 /* mmf input */
 static int mmf_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
 {
     MMFContext *mmf = s->priv_data;
     unsigned int tag;

     ByteIOContext *pb = s->pb;

     AVStream *st;

     int64_t file_size, size;

     int rate, params;
 
     tag = get_le32(pb);
     if (tag != MKTAG('M', 'M', 'M', 'D'))
         return -1;
     file_size = get_be32(pb);
 
     /* Skip some unused chunks that may or may not be present */
     for(;; url_fseek(pb, size, SEEK_CUR)) {
         tag = get_le32(pb);
         size = get_be32(pb);
         if(tag == MKTAG('C','N','T','I')) continue;
         if(tag == MKTAG('O','P','D','A')) continue;
         break;
     }
 
     /* Tag = "ATRx", where "x" = track number */

     if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {
         av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");
         return -1;
     }

     if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {
         av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);
         return -1;
     }
 
     get_byte(pb); /* format type */
     get_byte(pb); /* sequence type */
     params = get_byte(pb); /* (channel << 7) | (format << 4) | rate */
     rate = mmf_rate(params & 0x0f);
     if(rate  < 0) {
         av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");
         return -1;
     }
     get_byte(pb); /* wave base bit */
     get_byte(pb); /* time base d */
     get_byte(pb); /* time base g */
 
     /* Skip some unused chunks that may or may not be present */
     for(;; url_fseek(pb, size, SEEK_CUR)) {
         tag = get_le32(pb);
         size = get_be32(pb);
         if(tag == MKTAG('A','t','s','q')) continue;
         if(tag == MKTAG('A','s','p','I')) continue;
         break;
     }
 
     /* Make sure it's followed by an Awa chunk, aka wave data */
     if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {
         av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);
         return -1;
     }
     mmf->data_size = size;
 
     st = av_new_stream(s, 0);
     if (!st)

         return AVERROR(ENOMEM);

     st->codec->codec_type = CODEC_TYPE_AUDIO;
     st->codec->codec_id = CODEC_ID_ADPCM_YAMAHA;
     st->codec->sample_rate = rate;
     st->codec->channels = 1;

     st->codec->bits_per_coded_sample = 4;
     st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_coded_sample;

     av_set_pts_info(st, 64, 1, st->codec->sample_rate);

 
     return 0;
 }
 
 #define MAX_SIZE 4096
 
 static int mmf_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
 {
     MMFContext *mmf = s->priv_data;
     AVStream *st;
     int ret, size;
 

     if (url_feof(s->pb))

         return AVERROR(EIO);

     st = s->streams[0];
 
     size = MAX_SIZE;
     if(size > mmf->data_size)
         size = mmf->data_size;
 
     if(!size)

         return AVERROR(EIO);

     if (av_new_packet(pkt, size))

         return AVERROR(EIO);

     pkt->stream_index = 0;
 

     ret = get_buffer(s->pb, pkt->data, pkt->size);

     if (ret < 0)
         av_free_packet(pkt);
 
     mmf->data_size -= ret;
 
     pkt->size = ret;
     return ret;
 }
 

 #if CONFIG_MMF_DEMUXER

 AVInputFormat mmf_demuxer = {

     "mmf",

     NULL_IF_CONFIG_SMALL("Yamaha SMAF"),

     sizeof(MMFContext),
     mmf_probe,
     mmf_read_header,
     mmf_read_packet,

     NULL,

     pcm_read_seek,

 };

 #endif

 #if CONFIG_MMF_MUXER

 AVOutputFormat mmf_muxer = {

     "mmf",

     NULL_IF_CONFIG_SMALL("Yamaha SMAF"),

     "application/vnd.smaf",
     "mmf",
     sizeof(MMFContext),
     CODEC_ID_ADPCM_YAMAHA,
     CODEC_ID_NONE,
     mmf_write_header,
     mmf_write_packet,
     mmf_write_trailer,
 };

 #endif