2 * Bethsoft VID format Demuxer
3 * Copyright (c) 2007 Nicholas Tung
5 * This file is part of FFmpeg.
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.
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.
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
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
31 #include "bethsoftvideo.h"
33 typedef struct BVID_DemuxContext
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;
41 /** video presentation time stamp.
42 * delay = 16 milliseconds * (global_delay + per_frame_delay) */
49 static int vid_probe(AVProbeData *p)
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))
55 return AVPROBE_SCORE_MAX;
58 static int vid_read_header(AVFormatContext *s,
59 AVFormatParameters *ap)
61 BVID_DemuxContext *vid = s->priv_data; // permanent data outside of function
62 ByteIOContext *pb = &s->pb; // io to file
65 /* load main header. Contents:
67 * int16s: always_512, nframes, width, height, delay, always_14
69 url_fseek(pb, 5, SEEK_CUR);
70 vid->nframes = get_le16(pb);
72 // FFmpeg central code will use this; don't need to return or anything
73 // initialize the bethsoft codec
74 stream = av_new_stream(s, 0);
77 av_set_pts_info(stream, 32, 1, 60); // 16 ms increments, i.e. 60 fps
78 stream->codec->codec_type = CODEC_TYPE_VIDEO;
79 stream->codec->codec_id = CODEC_ID_BETHSOFTVID;
80 stream->codec->width = get_le16(pb);
81 stream->codec->height = get_le16(pb);
82 stream->codec->pix_fmt = PIX_FMT_PAL8;
83 vid->bethsoft_global_delay = get_le16(pb);
86 // done with video codec, set up audio codec
87 stream = av_new_stream(s, 0);
90 stream->codec->codec_type = CODEC_TYPE_AUDIO;
91 stream->codec->codec_id = CODEC_ID_PCM_U8;
92 stream->codec->channels = 1;
93 stream->codec->sample_rate = 11025;
94 stream->codec->bits_per_sample = 8;
95 stream->codec->bit_rate = stream->codec->channels * stream->codec->sample_rate * stream->codec->bits_per_sample;
100 #define BUFFER_PADDING_SIZE 1000
101 static int read_frame(BVID_DemuxContext *vid, ByteIOContext *pb, AVPacket *pkt,
102 uint8_t block_type, AVFormatContext *s, int npixels)
104 uint8_t * vidbuf_start = NULL;
105 int vidbuf_nbytes = 0;
107 int bytes_copied = 0;
109 size_t vidbuf_capacity;
111 vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
113 return AVERROR_NOMEM;
115 // save the file position for the packet, include block type
116 position = url_ftell(pb) - 1;
118 // set the block type for the decoder
119 vidbuf_start[vidbuf_nbytes++] = block_type;
121 // get the video delay (next int16), and set the presentation time
122 vid->video_pts += vid->bethsoft_global_delay + get_le16(pb);
124 // set the y offset if it exists (decoder header data should be in data section)
125 if(block_type == VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK){
126 if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2)
132 vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
134 return AVERROR_NOMEM;
136 rle_num_bytes = get_byte(pb);
137 vidbuf_start[vidbuf_nbytes++] = rle_num_bytes;
139 if(rle_num_bytes > 0x80){ // rle sequence
140 if(block_type == VIDEO_FULL_FRAME_BLOCK)
141 vidbuf_start[vidbuf_nbytes++] = get_byte(pb);
142 bytes_copied += rle_num_bytes - 0x80;
143 } else if(rle_num_bytes){ // plain sequence
144 if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], rle_num_bytes) != rle_num_bytes)
146 vidbuf_nbytes += rle_num_bytes;
147 bytes_copied += rle_num_bytes;
149 if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
150 // may contain a 0 byte even if read all pixels
152 url_fseek(pb, -1, SEEK_CUR);
155 if(bytes_copied > npixels)
157 } while(rle_num_bytes);
159 // copy data into packet
160 if(av_new_packet(pkt, vidbuf_nbytes) < 0)
162 memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
163 av_free(vidbuf_start);
166 pkt->stream_index = 0; // use the video decoder, which was initialized as the first stream
167 pkt->pts = vid->video_pts;
169 vid->nframes--; // used to check if all the frames were read
170 return vidbuf_nbytes;
172 av_free(vidbuf_start);
176 static int vid_read_packet(AVFormatContext *s,
179 BVID_DemuxContext *vid = s->priv_data; // permanent data outside of function
180 ByteIOContext *pb = &s->pb; // io to file
181 unsigned char block_type; // block type
185 if(vid->is_finished || url_feof(pb))
188 block_type = get_byte(pb);
191 url_fseek(pb, -1, SEEK_CUR); // include block type
192 ret_value = av_get_packet(pb, pkt, 3 * VID_PALETTE_NUMCOLORS + 1);
193 if(ret_value != 3 * VID_PALETTE_NUMCOLORS + 1){
197 pkt->stream_index = 0;
200 case FIRST_AUDIO_BLOCK:
201 get_le16(pb); // some unused constant
202 // soundblaster DAC used for sample rate, as on specification page (link above)
203 s->streams[1]->codec->sample_rate = 1000000 / (256 - get_byte(pb));
204 s->streams[1]->codec->bit_rate = s->streams[1]->codec->channels * s->streams[1]->codec->sample_rate * s->streams[1]->codec->bits_per_sample;
206 audio_length = get_le16(pb);
207 ret_value = av_get_packet(pb, pkt, audio_length);
208 pkt->stream_index = 1;
209 return (ret_value != audio_length ? AVERROR_IO : ret_value);
211 case VIDEO_DIFFERENCE_FRAME_BLOCK:
212 case VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK:
213 case VIDEO_FULL_FRAME_BLOCK:
214 return read_frame(vid, pb, pkt, block_type, s,
215 s->streams[0]->codec->width * s->streams[0]->codec->height);
218 if(vid->nframes != 0)
219 av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
220 vid->is_finished = 1;
223 av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
224 block_type, block_type, block_type); return -1;
230 AVInputFormat bethsoftvid_demuxer = {
232 "Bethesda Softworks 'Daggerfall' VID format",
233 sizeof(BVID_DemuxContext),