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 libavformat/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 "libavutil/intreadwrite.h"
  31 #include "avformat.h"
  32 #include "libavcodec/bethsoftvideo.h"
  33
  34 typedef struct BVID_DemuxContext
  35 {
  36     int nframes;
  37     /** delay value between frames, added to individual frame delay.
  38      * custom units, which will be added to other custom units (~=16ms according
  39      * to free, unofficial documentation) */
  40     int bethsoft_global_delay;
  41
  42     /** video presentation time stamp.
  43      * delay = 16 milliseconds * (global_delay + per_frame_delay) */
  44     int video_pts;
  45
  46     int is_finished;
  47
  48 } BVID_DemuxContext;
  49
  50 static int vid_probe(AVProbeData *p)
  51 {
  52     // little endian VID tag, file starts with "VID\0"
  53     if (AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))
  54         return 0;
  55
  56     return AVPROBE_SCORE_MAX;
  57 }
  58
  59 static int vid_read_header(AVFormatContext *s,
  60                             AVFormatParameters *ap)
  61 {
  62     BVID_DemuxContext *vid = s->priv_data;
  63     ByteIOContext *pb = s->pb;
  64     AVStream *stream;
  65
  66     /* load main header. Contents:
  67     *    bytes: 'V' 'I' 'D'
  68     *    int16s: always_512, nframes, width, height, delay, always_14
  69     */
  70     url_fseek(pb, 5, SEEK_CUR);
  71     vid->nframes = get_le16(pb);
  72
  73     stream = av_new_stream(s, 0);
  74     if (!stream)
  75         return AVERROR(ENOMEM);
  76     av_set_pts_info(stream, 32, 1, 60);     // 16 ms increments, i.e. 60 fps
  77     stream->codec->codec_type = CODEC_TYPE_VIDEO;
  78     stream->codec->codec_id = CODEC_ID_BETHSOFTVID;
  79     stream->codec->width = get_le16(pb);
  80     stream->codec->height = get_le16(pb);
  81     stream->codec->pix_fmt = PIX_FMT_PAL8;
  82     vid->bethsoft_global_delay = get_le16(pb);
  83     get_le16(pb);
  84
  85     // done with video codec, set up audio codec
  86     stream = av_new_stream(s, 0);
  87     if (!stream)
  88         return AVERROR(ENOMEM);
  89     stream->codec->codec_type = CODEC_TYPE_AUDIO;
  90     stream->codec->codec_id = CODEC_ID_PCM_U8;
  91     stream->codec->channels = 1;
  92     stream->codec->sample_rate = 11025;
  93     stream->codec->bits_per_coded_sample = 8;
  94     stream->codec->bit_rate = stream->codec->channels * stream->codec->sample_rate * stream->codec->bits_per_coded_sample;
  95
  96     return 0;
  97 }
  98
  99 #define BUFFER_PADDING_SIZE 1000
 100 static int read_frame(BVID_DemuxContext *vid, ByteIOContext *pb, AVPacket *pkt,
 101                       uint8_t block_type, AVFormatContext *s, int npixels)
 102 {
 103     uint8_t * vidbuf_start = NULL;
 104     int vidbuf_nbytes = 0;
 105     int code;
 106     int bytes_copied = 0;
 107     int position;
 108     unsigned int vidbuf_capacity;
 109
 110     vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
 111     if(!vidbuf_start)
 112         return AVERROR(ENOMEM);
 113
 114     // save the file position for the packet, include block type
 115     position = url_ftell(pb) - 1;
 116
 117     vidbuf_start[vidbuf_nbytes++] = block_type;
 118
 119     // get the video delay (next int16), and set the presentation time
 120     vid->video_pts += vid->bethsoft_global_delay + get_le16(pb);
 121
 122     // set the y offset if it exists (decoder header data should be in data section)
 123     if(block_type == VIDEO_YOFF_P_FRAME){
 124         if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2)
 125             goto fail;
 126         vidbuf_nbytes += 2;
 127     }
 128
 129     do{
 130         vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
 131         if(!vidbuf_start)
 132             return AVERROR(ENOMEM);
 133
 134         code = get_byte(pb);
 135         vidbuf_start[vidbuf_nbytes++] = code;
 136
 137         if(code >= 0x80){ // rle sequence
 138             if(block_type == VIDEO_I_FRAME)
 139                 vidbuf_start[vidbuf_nbytes++] = get_byte(pb);
 140         } else if(code){ // plain sequence
 141             if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], code) != code)
 142                 goto fail;
 143             vidbuf_nbytes += code;
 144         }
 145         bytes_copied += code & 0x7F;
 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(code);
 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(EIO);
 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 * 256 + 1);
 190             if(ret_value != 3 * 256 + 1){
 191                 av_free_packet(pkt);
 192                 return AVERROR(EIO);
 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_coded_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(EIO) : ret_value;
 207
 208         case VIDEO_P_FRAME:
 209         case VIDEO_YOFF_P_FRAME:
 210         case VIDEO_I_FRAME:
 211             return read_frame(vid, pb, pkt, block_type, s,
 212                               s->streams[0]->codec->width * s->streams[0]->codec->height);
 213
 214         case EOF_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(EIO);
 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     NULL_IF_CONFIG_SMALL("Bethesda Softworks VID format"),
 230     sizeof(BVID_DemuxContext),
 231     vid_probe,
 232     vid_read_header,
 233     vid_read_packet,
 234 };