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 "libavcodec/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 (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(ENOMEM);
  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(ENOMEM);
  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 code;
 105     int bytes_copied = 0;
 106     int position;
 107     unsigned int vidbuf_capacity;
 108
 109     vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
 110     if(!vidbuf_start)
 111         return AVERROR(ENOMEM);
 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_YOFF_P_FRAME){
 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(ENOMEM);
 132
 133         code = get_byte(pb);
 134         vidbuf_start[vidbuf_nbytes++] = code;
 135
 136         if(code >= 0x80){ // rle sequence
 137             if(block_type == VIDEO_I_FRAME)
 138                 vidbuf_start[vidbuf_nbytes++] = get_byte(pb);
 139         } else if(code){ // plain sequence
 140             if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], code) != code)
 141                 goto fail;
 142             vidbuf_nbytes += code;
 143         }
 144         bytes_copied += code & 0x7F;
 145         if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
 146             // may contain a 0 byte even if read all pixels
 147             if(get_byte(pb))
 148                 url_fseek(pb, -1, SEEK_CUR);
 149             break;
 150         }
 151         if(bytes_copied > npixels)
 152             goto fail;
 153     } while(code);
 154
 155     // copy data into packet
 156     if(av_new_packet(pkt, vidbuf_nbytes) < 0)
 157         goto fail;
 158     memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
 159     av_free(vidbuf_start);
 160
 161     pkt->pos = position;
 162     pkt->stream_index = 0;  // use the video decoder, which was initialized as the first stream
 163     pkt->pts = vid->video_pts;
 164
 165     vid->nframes--;  // used to check if all the frames were read
 166     return vidbuf_nbytes;
 167 fail:
 168     av_free(vidbuf_start);
 169     return -1;
 170 }
 171
 172 static int vid_read_packet(AVFormatContext *s,
 173                            AVPacket *pkt)
 174 {
 175     BVID_DemuxContext *vid = s->priv_data;
 176     ByteIOContext *pb = s->pb;
 177     unsigned char block_type;
 178     int audio_length;
 179     int ret_value;
 180
 181     if(vid->is_finished || url_feof(pb))
 182         return AVERROR(EIO);
 183
 184     block_type = get_byte(pb);
 185     switch(block_type){
 186         case PALETTE_BLOCK:
 187             url_fseek(pb, -1, SEEK_CUR);     // include block type
 188             ret_value = av_get_packet(pb, pkt, 3 * 256 + 1);
 189             if(ret_value != 3 * 256 + 1){
 190                 av_free_packet(pkt);
 191                 return AVERROR(EIO);
 192             }
 193             pkt->stream_index = 0;
 194             return ret_value;
 195
 196         case FIRST_AUDIO_BLOCK:
 197             get_le16(pb);
 198             // soundblaster DAC used for sample rate, as on specification page (link above)
 199             s->streams[1]->codec->sample_rate = 1000000 / (256 - get_byte(pb));
 200             s->streams[1]->codec->bit_rate = s->streams[1]->codec->channels * s->streams[1]->codec->sample_rate * s->streams[1]->codec->bits_per_sample;
 201         case AUDIO_BLOCK:
 202             audio_length = get_le16(pb);
 203             ret_value = av_get_packet(pb, pkt, audio_length);
 204             pkt->stream_index = 1;
 205             return ret_value != audio_length ? AVERROR(EIO) : ret_value;
 206
 207         case VIDEO_P_FRAME:
 208         case VIDEO_YOFF_P_FRAME:
 209         case VIDEO_I_FRAME:
 210             return read_frame(vid, pb, pkt, block_type, s,
 211                               s->streams[0]->codec->width * s->streams[0]->codec->height);
 212
 213         case EOF_BLOCK:
 214             if(vid->nframes != 0)
 215                 av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
 216             vid->is_finished = 1;
 217             return AVERROR(EIO);
 218         default:
 219             av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
 220                    block_type, block_type, block_type); return -1;
 221     }
 222
 223     return 0;
 224 }
 225
 226 AVInputFormat bethsoftvid_demuxer = {
 227     "bethsoftvid",
 228     NULL_IF_CONFIG_SMALL("Bethesda Softworks VID format"),
 229     sizeof(BVID_DemuxContext),
 230     vid_probe,
 231     vid_read_header,
 232     vid_read_packet,
 233 };