df338906c8e9df6068728df7215674cf757a3729
[ffmpeg.git] / libavformat / bethsoftvid.c
1 /*
2  * Bethsoft VID format Demuxer
3  * Copyright (c) 2007 Nicholas Tung
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 /**
23  * @file bethsoftvid.c
24  * @brief Bethesda Softworks VID (.vid) file demuxer
25  * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
26  * @sa http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
27  * @sa http://www.svatopluk.com/andux/docs/dfvid.html
28  */
29
30 #include "avformat.h"
31 #include "bethsoftvideo.h"
32
33 typedef struct BVID_DemuxContext
34 {
35     int nframes;
36     /** delay value between frames, added to individual frame delay.
37      * custom units, which will be added to other custom units (~=16ms according
38      * to free, unofficial documentation) */
39     int bethsoft_global_delay;
40
41     /** video presentation time stamp.
42      * delay = 16 milliseconds * (global_delay + per_frame_delay) */
43     int video_pts;
44
45     int is_finished;
46
47 } BVID_DemuxContext;
48
49 static int vid_probe(AVProbeData *p)
50 {
51     // little endian VID tag, file starts with "VID\0"
52     if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))
53         return 0;
54
55     return AVPROBE_SCORE_MAX;
56 }
57
58 static int vid_read_header(AVFormatContext *s,
59                             AVFormatParameters *ap)
60 {
61     BVID_DemuxContext *vid = s->priv_data;
62     ByteIOContext *pb = &s->pb;
63     AVStream *stream;
64
65     /* load main header. Contents:
66     *    bytes: 'V' 'I' 'D'
67     *    int16s: always_512, nframes, width, height, delay, always_14
68     */
69     url_fseek(pb, 5, SEEK_CUR);
70     vid->nframes = get_le16(pb);
71
72     stream = av_new_stream(s, 0);
73     if (!stream)
74         return AVERROR_NOMEM;
75     av_set_pts_info(stream, 32, 1, 60);     // 16 ms increments, i.e. 60 fps
76     stream->codec->codec_type = CODEC_TYPE_VIDEO;
77     stream->codec->codec_id = CODEC_ID_BETHSOFTVID;
78     stream->codec->width = get_le16(pb);
79     stream->codec->height = get_le16(pb);
80     stream->codec->pix_fmt = PIX_FMT_PAL8;
81     vid->bethsoft_global_delay = get_le16(pb);
82     get_le16(pb);
83
84     // done with video codec, set up audio codec
85     stream = av_new_stream(s, 0);
86     if (!stream)
87         return AVERROR_NOMEM;
88     stream->codec->codec_type = CODEC_TYPE_AUDIO;
89     stream->codec->codec_id = CODEC_ID_PCM_U8;
90     stream->codec->channels = 1;
91     stream->codec->sample_rate = 11025;
92     stream->codec->bits_per_sample = 8;
93     stream->codec->bit_rate = stream->codec->channels * stream->codec->sample_rate * stream->codec->bits_per_sample;
94
95     return 0;
96 }
97
98 #define BUFFER_PADDING_SIZE 1000
99 static int read_frame(BVID_DemuxContext *vid, ByteIOContext *pb, AVPacket *pkt,
100                       uint8_t block_type, AVFormatContext *s, int npixels)
101 {
102     uint8_t * vidbuf_start = NULL;
103     int vidbuf_nbytes = 0;
104     int rle_num_bytes;
105     int bytes_copied = 0;
106     int position;
107     size_t vidbuf_capacity;
108
109     vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
110     if(!vidbuf_start)
111         return AVERROR_NOMEM;
112
113     // save the file position for the packet, include block type
114     position = url_ftell(pb) - 1;
115
116     vidbuf_start[vidbuf_nbytes++] = block_type;
117
118     // get the video delay (next int16), and set the presentation time
119     vid->video_pts += vid->bethsoft_global_delay + get_le16(pb);
120
121     // set the y offset if it exists (decoder header data should be in data section)
122     if(block_type == VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK){
123         if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2)
124             goto fail;
125         vidbuf_nbytes += 2;
126     }
127
128     do{
129         vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
130         if(!vidbuf_start)
131             return AVERROR_NOMEM;
132
133         rle_num_bytes = get_byte(pb);
134         vidbuf_start[vidbuf_nbytes++] = rle_num_bytes;
135
136         if(rle_num_bytes > 0x80){ // rle sequence
137             if(block_type == VIDEO_FULL_FRAME_BLOCK)
138                 vidbuf_start[vidbuf_nbytes++] = get_byte(pb);
139             bytes_copied += rle_num_bytes - 0x80;
140         } else if(rle_num_bytes){ // plain sequence
141             if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], rle_num_bytes) != rle_num_bytes)
142                 goto fail;
143             vidbuf_nbytes += rle_num_bytes;
144             bytes_copied += rle_num_bytes;
145         }
146         if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
147             // may contain a 0 byte even if read all pixels
148             if(get_byte(pb))
149                 url_fseek(pb, -1, SEEK_CUR);
150             break;
151         }
152         if(bytes_copied > npixels)
153             goto fail;
154     } while(rle_num_bytes);
155
156     // copy data into packet
157     if(av_new_packet(pkt, vidbuf_nbytes) < 0)
158         goto fail;
159     memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
160     av_free(vidbuf_start);
161
162     pkt->pos = position;
163     pkt->stream_index = 0;  // use the video decoder, which was initialized as the first stream
164     pkt->pts = vid->video_pts;
165
166     vid->nframes--;  // used to check if all the frames were read
167     return vidbuf_nbytes;
168 fail:
169     av_free(vidbuf_start);
170     return -1;
171 }
172
173 static int vid_read_packet(AVFormatContext *s,
174                            AVPacket *pkt)
175 {
176     BVID_DemuxContext *vid = s->priv_data;
177     ByteIOContext *pb = &s->pb;
178     unsigned char block_type;
179     int audio_length;
180     int ret_value;
181
182     if(vid->is_finished || url_feof(pb))
183         return AVERROR_IO;
184
185     block_type = get_byte(pb);
186     switch(block_type){
187         case PALETTE_BLOCK:
188             url_fseek(pb, -1, SEEK_CUR);     // include block type
189             ret_value = av_get_packet(pb, pkt, 3 * VID_PALETTE_NUMCOLORS + 1);
190             if(ret_value != 3 * VID_PALETTE_NUMCOLORS + 1){
191                 av_free_packet(pkt);
192                 return AVERROR_IO;
193             }
194             pkt->stream_index = 0;
195             return ret_value;
196
197         case FIRST_AUDIO_BLOCK:
198             get_le16(pb);
199             // soundblaster DAC used for sample rate, as on specification page (link above)
200             s->streams[1]->codec->sample_rate = 1000000 / (256 - get_byte(pb));
201             s->streams[1]->codec->bit_rate = s->streams[1]->codec->channels * s->streams[1]->codec->sample_rate * s->streams[1]->codec->bits_per_sample;
202         case AUDIO_BLOCK:
203             audio_length = get_le16(pb);
204             ret_value = av_get_packet(pb, pkt, audio_length);
205             pkt->stream_index = 1;
206             return (ret_value != audio_length ? AVERROR_IO : ret_value);
207
208         case VIDEO_DIFFERENCE_FRAME_BLOCK:
209         case VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK:
210         case VIDEO_FULL_FRAME_BLOCK:
211             return read_frame(vid, pb, pkt, block_type, s,
212                               s->streams[0]->codec->width * s->streams[0]->codec->height);
213
214         case FINISHED_BLOCK:
215             if(vid->nframes != 0)
216                 av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
217             vid->is_finished = 1;
218             return AVERROR_IO;
219         default:
220             av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
221                    block_type, block_type, block_type); return -1;
222     }
223
224     return 0;
225 }
226
227 AVInputFormat bethsoftvid_demuxer = {
228     "bethsoftvid",
229     "Bethesda Softworks 'Daggerfall' VID format",
230     sizeof(BVID_DemuxContext),
231     vid_probe,
232     vid_read_header,
233     vid_read_packet,
234 };