/*

  * 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 "internal.h"

 #include "avio_internal.h"

 #include "pcm.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(AVIOContext *pb, int64_t start)

 {

     int64_t pos;

     pos = avio_tell(pb);

     avio_seek(pb, start - 4, SEEK_SET);

     avio_wb32(pb, (uint32_t)(pos - start));

     avio_seek(pb, pos, SEEK_SET);

 }
 
 static int mmf_write_header(AVFormatContext *s)
 {
     MMFContext *mmf = s->priv_data;

     AVIOContext *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, supported are 4000, 8000, 11025, 22050 and 44100\n", s->streams[0]->codec->sample_rate);

         return -1;
     }

     ffio_wfourcc(pb, "MMMD");

     avio_wb32(pb, 0);

     pos = ff_start_tag(pb, "CNTI");

     avio_w8(pb, 0); /* class */

     avio_w8(pb, 1); /* type */
     avio_w8(pb, 1); /* code type */

     avio_w8(pb, 0); /* status */
     avio_w8(pb, 0); /* counts */

     avio_write(pb, "VN:libavcodec,", sizeof("VN:libavcodec,") -1); /* metadata ("ST:songtitle,VN:version,...") */

     end_tag_be(pb, pos);
 

     avio_write(pb, "ATR\x00", 4);
     avio_wb32(pb, 0);

     mmf->atrpos = avio_tell(pb);

     avio_w8(pb, 0); /* format type */
     avio_w8(pb, 0); /* sequence type */
     avio_w8(pb, (0 << 7) | (1 << 4) | rate); /* (channel << 7) | (format << 4) | rate */
     avio_w8(pb, 0); /* wave base bit */
     avio_w8(pb, 2); /* time base d */
     avio_w8(pb, 2); /* time base g */

     ffio_wfourcc(pb, "Atsq");

     avio_wb32(pb, 16);

     mmf->atsqpos = avio_tell(pb);

     /* Will be filled on close */

     avio_write(pb, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16);

     mmf->awapos = ff_start_tag(pb, "Awa\x01");

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

     avio_flush(pb);

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

     AVIOContext *pb = s->pb;

     avio_write(pb, pkt->data, pkt->size);

     return 0;
 }
 
 /* Write a variable-length symbol */

 static void put_varlength(AVIOContext *pb, int val)

 {
     if(val < 128)

         avio_w8(pb, val);

     else {
         val -= 128;

         avio_w8(pb, 0x80 | val >> 7);
         avio_w8(pb, 0x7f & val);

     }
 }
 
 static int mmf_write_trailer(AVFormatContext *s)
 {

     AVIOContext *pb = s->pb;

     MMFContext *mmf = s->priv_data;

     int64_t pos, size;

     int gatetime;
 

     if (s->pb->seekable) {

         /* Fill in length fields */
         end_tag_be(pb, mmf->awapos);
         end_tag_be(pb, mmf->atrpos);
         end_tag_be(pb, 8);
 

         pos = avio_tell(pb);

         size = pos - mmf->awapos;
 
         /* Fill Atsq chunk */

         avio_seek(pb, mmf->atsqpos, SEEK_SET);

 
         /* "play wav" */

         avio_w8(pb, 0); /* start time */
         avio_w8(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 */

         avio_write(pb, "\xff\x00", 2); /* nop */

 
         /* "end of sequence" */

         avio_write(pb, "\x00\x00\x00\x00", 4);

         avio_seek(pb, pos, SEEK_SET);

         avio_flush(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)

 {
     MMFContext *mmf = s->priv_data;
     unsigned int tag;

     AVIOContext *pb = s->pb;

     AVStream *st;

     int64_t size;

     int rate, params;
 

     tag = avio_rl32(pb);

     if (tag != MKTAG('M', 'M', 'M', 'D'))
         return -1;

     avio_skip(pb, 4); /* file_size */

 
     /* Skip some unused chunks that may or may not be present */

     for(;; avio_skip(pb, size)) {

         tag = avio_rl32(pb);
         size = avio_rb32(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;
     }
 

     avio_r8(pb); /* format type */
     avio_r8(pb); /* sequence type */
     params = avio_r8(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;
     }

     avio_r8(pb); /* wave base bit */
     avio_r8(pb); /* time base d */
     avio_r8(pb); /* time base g */

 
     /* Skip some unused chunks that may or may not be present */

     for(;; avio_skip(pb, size)) {

         tag = avio_rl32(pb);
         size = avio_rb32(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 = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->codec_id = AV_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;

     avpriv_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;
     int ret, size;
 

     if (url_feof(s->pb))

         return AVERROR(EIO);

 
     size = MAX_SIZE;
     if(size > mmf->data_size)
         size = mmf->data_size;
 
     if(!size)

         return AVERROR(EIO);

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

     if (ret < 0)

         return ret;

     pkt->stream_index = 0;

     mmf->data_size -= ret;
 
     return ret;
 }
 

 #if CONFIG_MMF_DEMUXER

 AVInputFormat ff_mmf_demuxer = {

     .name           = "mmf",
     .long_name      = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
     .priv_data_size = sizeof(MMFContext),
     .read_probe     = mmf_probe,
     .read_header    = mmf_read_header,
     .read_packet    = mmf_read_packet,

     .read_seek      = ff_pcm_read_seek,

 };

 #endif

 #if CONFIG_MMF_MUXER

 AVOutputFormat ff_mmf_muxer = {

     .name              = "mmf",
     .long_name         = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
     .mime_type         = "application/vnd.smaf",
     .extensions        = "mmf",
     .priv_data_size    = sizeof(MMFContext),

     .audio_codec       = AV_CODEC_ID_ADPCM_YAMAHA,
     .video_codec       = AV_CODEC_ID_NONE,

     .write_header      = mmf_write_header,
     .write_packet      = mmf_write_packet,
     .write_trailer     = mmf_write_trailer,

 };

 #endif