1/*
2 * LXF demuxer
3 * Copyright (c) 2010 Tomas H��rdin
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 <inttypes.h>
23
24#include "libavutil/intreadwrite.h"
25#include "libavcodec/bytestream.h"
26#include "avformat.h"
27#include "internal.h"
28
29#define LXF_MAX_PACKET_HEADER_SIZE 256
30#define LXF_HEADER_DATA_SIZE    120
31#define LXF_IDENT               "LEITCH\0"
32#define LXF_IDENT_LENGTH        8
33#define LXF_SAMPLERATE          48000
34
35static const AVCodecTag lxf_tags[] = {
36    { AV_CODEC_ID_MJPEG,       0 },
37    { AV_CODEC_ID_MPEG1VIDEO,  1 },
38    { AV_CODEC_ID_MPEG2VIDEO,  2 },    //MpMl, 4:2:0
39    { AV_CODEC_ID_MPEG2VIDEO,  3 },    //MpPl, 4:2:2
40    { AV_CODEC_ID_DVVIDEO,     4 },    //DV25
41    { AV_CODEC_ID_DVVIDEO,     5 },    //DVCPRO
42    { AV_CODEC_ID_DVVIDEO,     6 },    //DVCPRO50
43    { AV_CODEC_ID_RAWVIDEO,    7 },    //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
44    { AV_CODEC_ID_RAWVIDEO,    8 },    //16-bit chroma key
45    { AV_CODEC_ID_MPEG2VIDEO,  9 },    //4:2:2 CBP ("Constrained Bytes per Gop")
46    { AV_CODEC_ID_NONE,        0 },
47};
48
49typedef struct {
50    int channels;                       ///< number of audio channels. zero means no audio
51    int frame_number;                   ///< current video frame
52    uint32_t video_format, packet_type, extended_size;
53} LXFDemuxContext;
54
55static int lxf_probe(AVProbeData *p)
56{
57    if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
58        return AVPROBE_SCORE_MAX;
59
60    return 0;
61}
62
63/**
64 * Verify the checksum of an LXF packet header
65 *
66 * @param[in] header the packet header to check
67 * @return zero if the checksum is OK, non-zero otherwise
68 */
69static int check_checksum(const uint8_t *header, int size)
70{
71    int x;
72    uint32_t sum = 0;
73
74    for (x = 0; x < size; x += 4)
75        sum += AV_RL32(&header[x]);
76
77    return sum;
78}
79
80/**
81 * Read input until we find the next ident. If found, copy it to the header buffer
82 *
83 * @param[out] header where to copy the ident to
84 * @return 0 if an ident was found, < 0 on I/O error
85 */
86static int sync(AVFormatContext *s, uint8_t *header)
87{
88    uint8_t buf[LXF_IDENT_LENGTH];
89    int ret;
90
91    if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
92        return ret < 0 ? ret : AVERROR_EOF;
93
94    while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
95        if (url_feof(s->pb))
96            return AVERROR_EOF;
97
98        memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
99        buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
100    }
101
102    memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
103
104    return 0;
105}
106
107/**
108 * Read and checksum the next packet header
109 *
110 * @return the size of the payload following the header or < 0 on failure
111 */
112static int get_packet_header(AVFormatContext *s)
113{
114    LXFDemuxContext *lxf = s->priv_data;
115    AVIOContext   *pb  = s->pb;
116    int track_size, samples, ret;
117    uint32_t version, audio_format, header_size, channels, tmp;
118    AVStream *st;
119    uint8_t header[LXF_MAX_PACKET_HEADER_SIZE];
120    const uint8_t *p = header + LXF_IDENT_LENGTH;
121
122    //find and read the ident
123    if ((ret = sync(s, header)) < 0)
124        return ret;
125
126    ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
127    if (ret != 8)
128        return ret < 0 ? ret : AVERROR_EOF;
129
130    version     = bytestream_get_le32(&p);
131    header_size = bytestream_get_le32(&p);
132    if (version > 1)
133        avpriv_request_sample(s, "Unknown format version %"PRIu32"\n", version);
134
135    if (header_size < (version ? 72 : 60) ||
136        header_size > LXF_MAX_PACKET_HEADER_SIZE ||
137        (header_size & 3)) {
138        av_log(s, AV_LOG_ERROR, "Invalid header size 0x%"PRIx32"\n", header_size);
139        return AVERROR_INVALIDDATA;
140    }
141
142    //read the rest of the packet header
143    if ((ret = avio_read(pb, header + (p - header),
144                          header_size - (p - header))) !=
145                          header_size - (p - header))
146        return ret < 0 ? ret : AVERROR_EOF;
147
148    if (check_checksum(header, header_size))
149        av_log(s, AV_LOG_ERROR, "checksum error\n");
150
151    lxf->packet_type = bytestream_get_le32(&p);
152    p += version ? 20 : 12;
153
154    lxf->extended_size = 0;
155    switch (lxf->packet_type) {
156    case 0:
157        //video
158        lxf->video_format = bytestream_get_le32(&p);
159        ret               = bytestream_get_le32(&p);
160        //skip VBI data and metadata
161        avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
162                      (int64_t)(uint32_t)AV_RL32(p + 12));
163        break;
164    case 1:
165        //audio
166        if (s->nb_streams < 2) {
167            av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
168            break;
169        }
170
171        if (version == 0)
172            p += 8;
173        audio_format = bytestream_get_le32(&p);
174        channels     = bytestream_get_le32(&p);
175        track_size   = bytestream_get_le32(&p);
176
177        st = s->streams[1];
178
179        //set codec based on specified audio bitdepth
180        //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
181        st->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
182
183        if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) {
184            av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
185            return AVERROR_PATCHWELCOME;
186        }
187
188        switch (st->codec->bits_per_coded_sample) {
189        case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
190        case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF;   break;
191        case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
192        case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;
193        default:
194            av_log(s, AV_LOG_WARNING,
195                   "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
196            return AVERROR_PATCHWELCOME;
197        }
198
199        samples = track_size * 8 / st->codec->bits_per_coded_sample;
200
201        //use audio packet size to determine video standard
202        //for NTSC we have one 8008-sample audio frame per five video frames
203        if (samples == LXF_SAMPLERATE * 5005 / 30000) {
204            avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
205        } else {
206            //assume PAL, but warn if we don't have 1920 samples
207            if (samples != LXF_SAMPLERATE / 25)
208                av_log(s, AV_LOG_WARNING,
209                       "video doesn't seem to be PAL or NTSC. guessing PAL\n");
210
211            avpriv_set_pts_info(s->streams[0], 64, 1, 25);
212        }
213
214        //TODO: warning if track mask != (1 << channels) - 1?
215        ret = av_popcount(channels) * track_size;
216
217        break;
218    default:
219        tmp = bytestream_get_le32(&p);
220        ret = bytestream_get_le32(&p);
221        if (tmp == 1)
222            lxf->extended_size = bytestream_get_le32(&p);
223        break;
224    }
225
226    return ret;
227}
228
229static int lxf_read_header(AVFormatContext *s)
230{
231    LXFDemuxContext *lxf = s->priv_data;
232    AVIOContext   *pb  = s->pb;
233    uint8_t header_data[LXF_HEADER_DATA_SIZE];
234    int ret;
235    AVStream *st;
236    uint32_t video_params, disk_params;
237    uint16_t record_date, expiration_date;
238
239    if ((ret = get_packet_header(s)) < 0)
240        return ret;
241
242    if (ret != LXF_HEADER_DATA_SIZE) {
243        av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
244               LXF_HEADER_DATA_SIZE, ret);
245        return AVERROR_INVALIDDATA;
246    }
247
248    if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
249        return ret < 0 ? ret : AVERROR_EOF;
250
251    if (!(st = avformat_new_stream(s, NULL)))
252        return AVERROR(ENOMEM);
253
254    st->duration          = AV_RL32(&header_data[32]);
255    video_params          = AV_RL32(&header_data[40]);
256    record_date           = AV_RL16(&header_data[56]);
257    expiration_date       = AV_RL16(&header_data[58]);
258    disk_params           = AV_RL32(&header_data[116]);
259
260    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
261    st->codec->bit_rate   = 1000000 * ((video_params >> 14) & 0xFF);
262    st->codec->codec_tag  = video_params & 0xF;
263    st->codec->codec_id   = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
264    st->need_parsing      = AVSTREAM_PARSE_HEADERS;
265
266    av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
267           record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
268           (record_date >> 11) & 0x1F);
269
270    av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
271           expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
272           (expiration_date >> 11) & 0x1F);
273
274    if ((video_params >> 22) & 1)
275        av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
276
277    if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
278        if (!(st = avformat_new_stream(s, NULL)))
279            return AVERROR(ENOMEM);
280
281        st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
282        st->codec->sample_rate = LXF_SAMPLERATE;
283        st->codec->channels    = lxf->channels;
284
285        avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
286    }
287
288    avio_skip(s->pb, lxf->extended_size);
289
290    return 0;
291}
292
293static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
294{
295    LXFDemuxContext *lxf = s->priv_data;
296    AVIOContext   *pb  = s->pb;
297    uint32_t stream;
298    int ret, ret2;
299
300    if ((ret = get_packet_header(s)) < 0)
301        return ret;
302
303    stream = lxf->packet_type;
304
305    if (stream > 1) {
306        av_log(s, AV_LOG_WARNING,
307               "got packet with illegal stream index %"PRIu32"\n", stream);
308        return AVERROR(EAGAIN);
309    }
310
311    if (stream == 1 && s->nb_streams < 2) {
312        av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
313        return AVERROR_INVALIDDATA;
314    }
315
316    if ((ret2 = av_new_packet(pkt, ret)) < 0)
317        return ret2;
318
319    if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
320        av_free_packet(pkt);
321        return ret2 < 0 ? ret2 : AVERROR_EOF;
322    }
323
324    pkt->stream_index = stream;
325
326    if (!stream) {
327        //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
328        if (((lxf->video_format >> 22) & 0x3) < 2)
329            pkt->flags |= AV_PKT_FLAG_KEY;
330
331        pkt->dts = lxf->frame_number++;
332    }
333
334    return ret;
335}
336
337AVInputFormat ff_lxf_demuxer = {
338    .name           = "lxf",
339    .long_name      = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
340    .priv_data_size = sizeof(LXFDemuxContext),
341    .read_probe     = lxf_probe,
342    .read_header    = lxf_read_header,
343    .read_packet    = lxf_read_packet,
344    .codec_tag      = (const AVCodecTag* const []){lxf_tags, 0},
345};
346