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  1. /*
  2.  * LXF demuxer
  3.  * Copyright (c) 2010 Tomas Härdin
  4.  *
  5.  * This file is part of FFmpeg.
  6.  *
  7.  * FFmpeg is free software; you can redistribute it and/or
  8.  * modify it under the terms of the GNU Lesser General Public
  9.  * License as published by the Free Software Foundation; either
  10.  * version 2.1 of the License, or (at your option) any later version.
  11.  *
  12.  * FFmpeg is distributed in the hope that it will be useful,
  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15.  * Lesser General Public License for more details.
  16.  *
  17.  * You should have received a copy of the GNU Lesser General Public
  18.  * License along with FFmpeg; if not, write to the Free Software
  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20.  */
  21.  
  22. #include "libavutil/intreadwrite.h"
  23. #include "libavcodec/bytestream.h"
  24. #include "avformat.h"
  25. #include "internal.h"
  26.  
  27. #define LXF_MAX_PACKET_HEADER_SIZE 256
  28. #define LXF_HEADER_DATA_SIZE    120
  29. #define LXF_IDENT               "LEITCH\0"
  30. #define LXF_IDENT_LENGTH        8
  31. #define LXF_SAMPLERATE          48000
  32.  
  33. static const AVCodecTag lxf_tags[] = {
  34.     { AV_CODEC_ID_MJPEG,       0 },
  35.     { AV_CODEC_ID_MPEG1VIDEO,  1 },
  36.     { AV_CODEC_ID_MPEG2VIDEO,  2 },    //MpMl, 4:2:0
  37.     { AV_CODEC_ID_MPEG2VIDEO,  3 },    //MpPl, 4:2:2
  38.     { AV_CODEC_ID_DVVIDEO,     4 },    //DV25
  39.     { AV_CODEC_ID_DVVIDEO,     5 },    //DVCPRO
  40.     { AV_CODEC_ID_DVVIDEO,     6 },    //DVCPRO50
  41.     { AV_CODEC_ID_RAWVIDEO,    7 },    //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
  42.     { AV_CODEC_ID_RAWVIDEO,    8 },    //16-bit chroma key
  43.     { AV_CODEC_ID_MPEG2VIDEO,  9 },    //4:2:2 CBP ("Constrained Bytes per Gop")
  44.     { AV_CODEC_ID_NONE,        0 },
  45. };
  46.  
  47. typedef struct {
  48.     int channels;                       ///< number of audio channels. zero means no audio
  49.     int frame_number;                   ///< current video frame
  50.     uint32_t video_format, packet_type, extended_size;
  51. } LXFDemuxContext;
  52.  
  53. static int lxf_probe(AVProbeData *p)
  54. {
  55.     if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
  56.         return AVPROBE_SCORE_MAX;
  57.  
  58.     return 0;
  59. }
  60.  
  61. /**
  62.  * Verify the checksum of an LXF packet header
  63.  *
  64.  * @param[in] header the packet header to check
  65.  * @return zero if the checksum is OK, non-zero otherwise
  66.  */
  67. static int check_checksum(const uint8_t *header, int size)
  68. {
  69.     int x;
  70.     uint32_t sum = 0;
  71.  
  72.     for (x = 0; x < size; x += 4)
  73.         sum += AV_RL32(&header[x]);
  74.  
  75.     return sum;
  76. }
  77.  
  78. /**
  79.  * Read input until we find the next ident. If found, copy it to the header buffer
  80.  *
  81.  * @param[out] header where to copy the ident to
  82.  * @return 0 if an ident was found, < 0 on I/O error
  83.  */
  84. static int sync(AVFormatContext *s, uint8_t *header)
  85. {
  86.     uint8_t buf[LXF_IDENT_LENGTH];
  87.     int ret;
  88.  
  89.     if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
  90.         return ret < 0 ? ret : AVERROR_EOF;
  91.  
  92.     while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
  93.         if (url_feof(s->pb))
  94.             return AVERROR_EOF;
  95.  
  96.         memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
  97.         buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
  98.     }
  99.  
  100.     memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
  101.  
  102.     return 0;
  103. }
  104.  
  105. /**
  106.  * Read and checksum the next packet header
  107.  *
  108.  * @return the size of the payload following the header or < 0 on failure
  109.  */
  110. static int get_packet_header(AVFormatContext *s)
  111. {
  112.     LXFDemuxContext *lxf = s->priv_data;
  113.     AVIOContext   *pb  = s->pb;
  114.     int track_size, samples, ret;
  115.     uint32_t version, audio_format, header_size, channels, tmp;
  116.     AVStream *st;
  117.     uint8_t header[LXF_MAX_PACKET_HEADER_SIZE];
  118.     const uint8_t *p = header + LXF_IDENT_LENGTH;
  119.  
  120.     //find and read the ident
  121.     if ((ret = sync(s, header)) < 0)
  122.         return ret;
  123.  
  124.     ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
  125.     if (ret != 8)
  126.         return ret < 0 ? ret : AVERROR_EOF;
  127.  
  128.     version     = bytestream_get_le32(&p);
  129.     header_size = bytestream_get_le32(&p);
  130.     if (version > 1)
  131.         avpriv_request_sample(s, "Unknown format version %i\n", version);
  132.  
  133.     if (header_size < (version ? 72 : 60) ||
  134.         header_size > LXF_MAX_PACKET_HEADER_SIZE ||
  135.         (header_size & 3)) {
  136.         av_log(s, AV_LOG_ERROR, "Invalid header size 0x%x\n", header_size);
  137.         return AVERROR_INVALIDDATA;
  138.     }
  139.  
  140.     //read the rest of the packet header
  141.     if ((ret = avio_read(pb, header + (p - header),
  142.                           header_size - (p - header))) !=
  143.                           header_size - (p - header))
  144.         return ret < 0 ? ret : AVERROR_EOF;
  145.  
  146.     if (check_checksum(header, header_size))
  147.         av_log(s, AV_LOG_ERROR, "checksum error\n");
  148.  
  149.     lxf->packet_type = bytestream_get_le32(&p);
  150.     p += version ? 20 : 12;
  151.  
  152.     lxf->extended_size = 0;
  153.     switch (lxf->packet_type) {
  154.     case 0:
  155.         //video
  156.         lxf->video_format = bytestream_get_le32(&p);
  157.         ret               = bytestream_get_le32(&p);
  158.         //skip VBI data and metadata
  159.         avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
  160.                       (int64_t)(uint32_t)AV_RL32(p + 12));
  161.         break;
  162.     case 1:
  163.         //audio
  164.         if (s->nb_streams < 2) {
  165.             av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
  166.             break;
  167.         }
  168.  
  169.         if (version == 0)
  170.             p += 8;
  171.         audio_format = bytestream_get_le32(&p);
  172.         channels     = bytestream_get_le32(&p);
  173.         track_size   = bytestream_get_le32(&p);
  174.  
  175.         st = s->streams[1];
  176.  
  177.         //set codec based on specified audio bitdepth
  178.         //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
  179.         st->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
  180.  
  181.         if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) {
  182.             av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
  183.             return AVERROR_PATCHWELCOME;
  184.         }
  185.  
  186.         switch (st->codec->bits_per_coded_sample) {
  187.         case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
  188.         case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF;   break;
  189.         case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
  190.         case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;
  191.         default:
  192.             av_log(s, AV_LOG_WARNING,
  193.                    "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
  194.             return AVERROR_PATCHWELCOME;
  195.         }
  196.  
  197.         samples = track_size * 8 / st->codec->bits_per_coded_sample;
  198.  
  199.         //use audio packet size to determine video standard
  200.         //for NTSC we have one 8008-sample audio frame per five video frames
  201.         if (samples == LXF_SAMPLERATE * 5005 / 30000) {
  202.             avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
  203.         } else {
  204.             //assume PAL, but warn if we don't have 1920 samples
  205.             if (samples != LXF_SAMPLERATE / 25)
  206.                 av_log(s, AV_LOG_WARNING,
  207.                        "video doesn't seem to be PAL or NTSC. guessing PAL\n");
  208.  
  209.             avpriv_set_pts_info(s->streams[0], 64, 1, 25);
  210.         }
  211.  
  212.         //TODO: warning if track mask != (1 << channels) - 1?
  213.         ret = av_popcount(channels) * track_size;
  214.  
  215.         break;
  216.     default:
  217.         tmp = bytestream_get_le32(&p);
  218.         ret = bytestream_get_le32(&p);
  219.         if (tmp == 1)
  220.             lxf->extended_size = bytestream_get_le32(&p);
  221.         break;
  222.     }
  223.  
  224.     return ret;
  225. }
  226.  
  227. static int lxf_read_header(AVFormatContext *s)
  228. {
  229.     LXFDemuxContext *lxf = s->priv_data;
  230.     AVIOContext   *pb  = s->pb;
  231.     uint8_t header_data[LXF_HEADER_DATA_SIZE];
  232.     int ret;
  233.     AVStream *st;
  234.     uint32_t video_params, disk_params;
  235.     uint16_t record_date, expiration_date;
  236.  
  237.     if ((ret = get_packet_header(s)) < 0)
  238.         return ret;
  239.  
  240.     if (ret != LXF_HEADER_DATA_SIZE) {
  241.         av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
  242.                LXF_HEADER_DATA_SIZE, ret);
  243.         return AVERROR_INVALIDDATA;
  244.     }
  245.  
  246.     if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
  247.         return ret < 0 ? ret : AVERROR_EOF;
  248.  
  249.     if (!(st = avformat_new_stream(s, NULL)))
  250.         return AVERROR(ENOMEM);
  251.  
  252.     st->duration          = AV_RL32(&header_data[32]);
  253.     video_params          = AV_RL32(&header_data[40]);
  254.     record_date           = AV_RL16(&header_data[56]);
  255.     expiration_date       = AV_RL16(&header_data[58]);
  256.     disk_params           = AV_RL32(&header_data[116]);
  257.  
  258.     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
  259.     st->codec->bit_rate   = 1000000 * ((video_params >> 14) & 0xFF);
  260.     st->codec->codec_tag  = video_params & 0xF;
  261.     st->codec->codec_id   = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
  262.     st->need_parsing      = AVSTREAM_PARSE_HEADERS;
  263.  
  264.     av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
  265.            record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
  266.            (record_date >> 11) & 0x1F);
  267.  
  268.     av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
  269.            expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
  270.            (expiration_date >> 11) & 0x1F);
  271.  
  272.     if ((video_params >> 22) & 1)
  273.         av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
  274.  
  275.     if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
  276.         if (!(st = avformat_new_stream(s, NULL)))
  277.             return AVERROR(ENOMEM);
  278.  
  279.         st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
  280.         st->codec->sample_rate = LXF_SAMPLERATE;
  281.         st->codec->channels    = lxf->channels;
  282.  
  283.         avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
  284.     }
  285.  
  286.     avio_skip(s->pb, lxf->extended_size);
  287.  
  288.     return 0;
  289. }
  290.  
  291. static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
  292. {
  293.     LXFDemuxContext *lxf = s->priv_data;
  294.     AVIOContext   *pb  = s->pb;
  295.     uint32_t stream;
  296.     int ret, ret2;
  297.  
  298.     if ((ret = get_packet_header(s)) < 0)
  299.         return ret;
  300.  
  301.     stream = lxf->packet_type;
  302.  
  303.     if (stream > 1) {
  304.         av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
  305.         return AVERROR(EAGAIN);
  306.     }
  307.  
  308.     if (stream == 1 && s->nb_streams < 2) {
  309.         av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
  310.         return AVERROR_INVALIDDATA;
  311.     }
  312.  
  313.     if ((ret2 = av_new_packet(pkt, ret)) < 0)
  314.         return ret2;
  315.  
  316.     if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
  317.         av_free_packet(pkt);
  318.         return ret2 < 0 ? ret2 : AVERROR_EOF;
  319.     }
  320.  
  321.     pkt->stream_index = stream;
  322.  
  323.     if (!stream) {
  324.         //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
  325.         if (((lxf->video_format >> 22) & 0x3) < 2)
  326.             pkt->flags |= AV_PKT_FLAG_KEY;
  327.  
  328.         pkt->dts = lxf->frame_number++;
  329.     }
  330.  
  331.     return ret;
  332. }
  333.  
  334. AVInputFormat ff_lxf_demuxer = {
  335.     .name           = "lxf",
  336.     .long_name      = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
  337.     .priv_data_size = sizeof(LXFDemuxContext),
  338.     .read_probe     = lxf_probe,
  339.     .read_header    = lxf_read_header,
  340.     .read_packet    = lxf_read_packet,
  341.     .codec_tag      = (const AVCodecTag* const []){lxf_tags, 0},
  342. };
  343.