/*
  * LXF demuxer
  * Copyright (c) 2010 Tomas Härdin
  *
  * 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 "libavcodec/bytestream.h"

 #include "avformat.h"

 #include "internal.h"

 #define LXF_MAX_PACKET_HEADER_SIZE 256

 #define LXF_HEADER_DATA_SIZE    120
 #define LXF_IDENT               "LEITCH\0"
 #define LXF_IDENT_LENGTH        8
 #define LXF_SAMPLERATE          48000
 #define LXF_MAX_AUDIO_PACKET    (8008*15*4) ///< 15-channel 32-bit NTSC audio frame
 
 static const AVCodecTag lxf_tags[] = {

     { AV_CODEC_ID_MJPEG,       0 },
     { AV_CODEC_ID_MPEG1VIDEO,  1 },
     { AV_CODEC_ID_MPEG2VIDEO,  2 },    //MpMl, 4:2:0
     { AV_CODEC_ID_MPEG2VIDEO,  3 },    //MpPl, 4:2:2
     { AV_CODEC_ID_DVVIDEO,     4 },    //DV25
     { AV_CODEC_ID_DVVIDEO,     5 },    //DVCPRO
     { AV_CODEC_ID_DVVIDEO,     6 },    //DVCPRO50

     { AV_CODEC_ID_RAWVIDEO,    7 },    //AV_PIX_FMT_ARGB, where alpha is used for chroma keying

     { AV_CODEC_ID_RAWVIDEO,    8 },    //16-bit chroma key
     { AV_CODEC_ID_MPEG2VIDEO,  9 },    //4:2:2 CBP ("Constrained Bytes per Gop")
     { AV_CODEC_ID_NONE,        0 },

 };
 
 typedef struct {
     int channels;                       ///< number of audio channels. zero means no audio
     int frame_number;                   ///< current video frame

     uint32_t video_format, packet_type, extended_size;

 } LXFDemuxContext;
 
 static int lxf_probe(AVProbeData *p)
 {
     if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
         return AVPROBE_SCORE_MAX;
 
     return 0;
 }
 
 /**
  * Verify the checksum of an LXF packet header
  *
  * @param[in] header the packet header to check
  * @return zero if the checksum is OK, non-zero otherwise
  */

 static int check_checksum(const uint8_t *header, int size)

 {
     int x;
     uint32_t sum = 0;
 

     for (x = 0; x < size; x += 4)

         sum += AV_RL32(&header[x]);
 
     return sum;
 }
 
 /**
  * Read input until we find the next ident. If found, copy it to the header buffer
  *
  * @param[out] header where to copy the ident to
  * @return 0 if an ident was found, < 0 on I/O error
  */
 static int sync(AVFormatContext *s, uint8_t *header)
 {
     uint8_t buf[LXF_IDENT_LENGTH];
     int ret;
 

     if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)

         return ret < 0 ? ret : AVERROR_EOF;
 
     while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
         if (url_feof(s->pb))
             return AVERROR_EOF;
 
         memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);

         buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);

     }
 
     memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
 
     return 0;
 }
 
 /**
  * Read and checksum the next packet header
  *
  * @return the size of the payload following the header or < 0 on failure
  */

 static int get_packet_header(AVFormatContext *s)

 {

     LXFDemuxContext *lxf = s->priv_data;

     AVIOContext   *pb  = s->pb;

     int track_size, samples, ret;

     uint32_t version, audio_format, header_size, channels, tmp;

     AVStream *st;

     uint8_t header[LXF_MAX_PACKET_HEADER_SIZE];
     const uint8_t *p;

 
     //find and read the ident
     if ((ret = sync(s, header)) < 0)
         return ret;
 

     ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
     if (ret != 8)
         return ret < 0 ? ret : AVERROR_EOF;
 
     p = header + LXF_IDENT_LENGTH;
     version     = bytestream_get_le32(&p);
     header_size = bytestream_get_le32(&p);
     if (version > 1)
         av_log_ask_for_sample(s, "Unknown format version %i\n", version);
     if (header_size < (version ? 72 : 60) ||
         header_size > LXF_MAX_PACKET_HEADER_SIZE ||
         (header_size & 3)) {
         av_log(s, AV_LOG_ERROR, "Invalid header size 0x%x\n", header_size);
         return AVERROR_INVALIDDATA;
     }
 

     //read the rest of the packet header

     if ((ret = avio_read(pb, header + (p - header),
                           header_size - (p - header))) !=
                           header_size - (p - header)) {

         return ret < 0 ? ret : AVERROR_EOF;
     }
 

     if (check_checksum(header, header_size))

         av_log(s, AV_LOG_ERROR, "checksum error\n");
 

     lxf->packet_type = bytestream_get_le32(&p);
     p += version ? 20 : 12;

     lxf->extended_size = 0;
     switch (lxf->packet_type) {

     case 0:
         //video

         lxf->video_format = bytestream_get_le32(&p);
         ret               = bytestream_get_le32(&p);

         //skip VBI data and metadata

         avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
                       (int64_t)(uint32_t)AV_RL32(p + 12));

         break;
     case 1:
         //audio

         if (!s->streams || !(st = s->streams[1])) {

             av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
             break;
         }
 

         if (version == 0) p += 8;
         audio_format = bytestream_get_le32(&p);
         channels     = bytestream_get_le32(&p);
         track_size   = bytestream_get_le32(&p);
 

         //set codec based on specified audio bitdepth
         //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment

         st->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F;

         if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) {

             av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
             return AVERROR_PATCHWELCOME;
         }
 
         switch (st->codec->bits_per_coded_sample) {

         case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;

         case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF;   break;

         case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
         case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;

         default:
             av_log(s, AV_LOG_WARNING,
                    "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
             return AVERROR_PATCHWELCOME;
         }
 
         samples = track_size * 8 / st->codec->bits_per_coded_sample;
 
         //use audio packet size to determine video standard
         //for NTSC we have one 8008-sample audio frame per five video frames
         if (samples == LXF_SAMPLERATE * 5005 / 30000) {

             avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);

         } else {
             //assume PAL, but warn if we don't have 1920 samples
             if (samples != LXF_SAMPLERATE / 25)
                 av_log(s, AV_LOG_WARNING,
                        "video doesn't seem to be PAL or NTSC. guessing PAL\n");
 

             avpriv_set_pts_info(s->streams[0], 64, 1, 25);

         }
 
         //TODO: warning if track mask != (1 << channels) - 1?

         ret = av_popcount(channels) * track_size;

 
         break;
     default:

         tmp = bytestream_get_le32(&p);
         ret = bytestream_get_le32(&p);
         if (tmp == 1)
             lxf->extended_size = bytestream_get_le32(&p);

         break;
     }
 
     return ret;
 }
 

 static int lxf_read_header(AVFormatContext *s)

 {
     LXFDemuxContext *lxf = s->priv_data;

     AVIOContext   *pb  = s->pb;

     uint8_t header_data[LXF_HEADER_DATA_SIZE];

     int ret;
     AVStream *st;

     uint32_t video_params, disk_params;

     uint16_t record_date, expiration_date;
 

     if ((ret = get_packet_header(s)) < 0)

         return ret;
 
     if (ret != LXF_HEADER_DATA_SIZE) {
         av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
                LXF_HEADER_DATA_SIZE, ret);
         return AVERROR_INVALIDDATA;
     }
 

     if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)

         return ret < 0 ? ret : AVERROR_EOF;
 

     if (!(st = avformat_new_stream(s, NULL)))

         return AVERROR(ENOMEM);

 
     st->duration          = AV_RL32(&header_data[32]);
     video_params          = AV_RL32(&header_data[40]);
     record_date           = AV_RL16(&header_data[56]);
     expiration_date       = AV_RL16(&header_data[58]);
     disk_params           = AV_RL32(&header_data[116]);
 
     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codec->bit_rate   = 1000000 * ((video_params >> 14) & 0xFF);
     st->codec->codec_tag  = video_params & 0xF;
     st->codec->codec_id   = ff_codec_get_id(lxf_tags, st->codec->codec_tag);

     st->need_parsing      = AVSTREAM_PARSE_HEADERS;

 
     av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
            record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
            (record_date >> 11) & 0x1F);
 
     av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
            expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
            (expiration_date >> 11) & 0x1F);
 
     if ((video_params >> 22) & 1)
         av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
 

     if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {

         if (!(st = avformat_new_stream(s, NULL)))

             return AVERROR(ENOMEM);

 
         st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
         st->codec->sample_rate = LXF_SAMPLERATE;
         st->codec->channels    = lxf->channels;
 

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

     }
 

     avio_skip(s->pb, lxf->extended_size);

 
     return 0;
 }
 
 static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     LXFDemuxContext *lxf = s->priv_data;

     AVIOContext   *pb  = s->pb;

     AVStream *ast = NULL;

     uint32_t stream;

     int ret, ret2;
 

     if ((ret = get_packet_header(s)) < 0)

         return ret;
 

     stream = lxf->packet_type;

 
     if (stream > 1) {
         av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
         return AVERROR(EAGAIN);
     }
 
     if (stream == 1 && !(ast = s->streams[1])) {
         av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
         return AVERROR_INVALIDDATA;
     }
 
     //make sure the data fits in the de-planerization buffer
     if (ast && ret > LXF_MAX_AUDIO_PACKET) {
         av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n",
             ret, LXF_MAX_AUDIO_PACKET);
         return AVERROR_INVALIDDATA;
     }
 
     if ((ret2 = av_new_packet(pkt, ret)) < 0)
         return ret2;
 

     if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {

         av_free_packet(pkt);
         return ret2 < 0 ? ret2 : AVERROR_EOF;
     }
 
     pkt->stream_index = stream;
 

     if (!ast) {

         //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)

         if (((lxf->video_format >> 22) & 0x3) < 2)

             pkt->flags |= AV_PKT_FLAG_KEY;
 
         pkt->dts = lxf->frame_number++;
     }
 
     return ret;
 }
 

 AVInputFormat ff_lxf_demuxer = {

     .name           = "lxf",

     .long_name      = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),

     .priv_data_size = sizeof(LXFDemuxContext),
     .read_probe     = lxf_probe,
     .read_header    = lxf_read_header,
     .read_packet    = lxf_read_packet,
     .codec_tag      = (const AVCodecTag* const []){lxf_tags, 0},
 };