libavformat/avs.c

   1 /*
   2  * AVS demuxer.
   3  * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
   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 "avformat.h"
  23 #include "voc.h"
  24
  25
  26 typedef struct avs_format {
  27     voc_dec_context_t voc;
  28     AVStream *st_video;
  29     AVStream *st_audio;
  30     int width;
  31     int height;
  32     int bits_per_sample;
  33     int fps;
  34     int nb_frames;
  35     int remaining_frame_size;
  36     int remaining_audio_size;
  37 } avs_format_t;
  38
  39 typedef enum avs_block_type {
  40     AVS_VIDEO     = 0x01,
  41     AVS_AUDIO     = 0x02,
  42     AVS_PALETTE   = 0x03,
  43     AVS_GAME_DATA = 0x04,
  44 } avs_block_type_t;
  45
  46 static int avs_probe(AVProbeData * p)
  47 {
  48     const uint8_t *d;
  49
  50     d = p->buf;
  51     if (d[0] == 'w' && d[1] == 'W' && d[2] == 0x10 && d[3] == 0)
  52         return 50;
  53
  54     return 0;
  55 }
  56
  57 static int avs_read_header(AVFormatContext * s, AVFormatParameters * ap)
  58 {
  59     avs_format_t *avs = s->priv_data;
  60
  61     s->ctx_flags |= AVFMTCTX_NOHEADER;
  62
  63     url_fskip(s->pb, 4);
  64     avs->width = get_le16(s->pb);
  65     avs->height = get_le16(s->pb);
  66     avs->bits_per_sample = get_le16(s->pb);
  67     avs->fps = get_le16(s->pb);
  68     avs->nb_frames = get_le32(s->pb);
  69     avs->remaining_frame_size = 0;
  70     avs->remaining_audio_size = 0;
  71
  72     avs->st_video = avs->st_audio = NULL;
  73
  74     if (avs->width != 318 || avs->height != 198)
  75         av_log(s, AV_LOG_ERROR, "This avs pretend to be %dx%d "
  76                "when the avs format is supposed to be 318x198 only.\n",
  77                avs->width, avs->height);
  78
  79     return 0;
  80 }
  81
  82 static int
  83 avs_read_video_packet(AVFormatContext * s, AVPacket * pkt,
  84                       avs_block_type_t type, int sub_type, int size,
  85                       uint8_t * palette, int palette_size)
  86 {
  87     avs_format_t *avs = s->priv_data;
  88     int ret;
  89
  90     ret = av_new_packet(pkt, size + palette_size);
  91     if (ret < 0)
  92         return ret;
  93
  94     if (palette_size) {
  95         pkt->data[0] = 0x00;
  96         pkt->data[1] = 0x03;
  97         pkt->data[2] = palette_size & 0xFF;
  98         pkt->data[3] = (palette_size >> 8) & 0xFF;
  99         memcpy(pkt->data + 4, palette, palette_size - 4);
 100     }
 101
 102     pkt->data[palette_size + 0] = sub_type;
 103     pkt->data[palette_size + 1] = type;
 104     pkt->data[palette_size + 2] = size & 0xFF;
 105     pkt->data[palette_size + 3] = (size >> 8) & 0xFF;
 106     ret = get_buffer(s->pb, pkt->data + palette_size + 4, size - 4) + 4;
 107     if (ret < size) {
 108         av_free_packet(pkt);
 109         return AVERROR(EIO);
 110     }
 111
 112     pkt->size = ret + palette_size;
 113     pkt->stream_index = avs->st_video->index;
 114     if (sub_type == 0)
 115         pkt->flags |= PKT_FLAG_KEY;
 116
 117     return 0;
 118 }
 119
 120 static int avs_read_audio_packet(AVFormatContext * s, AVPacket * pkt)
 121 {
 122     avs_format_t *avs = s->priv_data;
 123     int ret, size;
 124
 125     size = url_ftell(s->pb);
 126     ret = voc_get_packet(s, pkt, avs->st_audio, avs->remaining_audio_size);
 127     size = url_ftell(s->pb) - size;
 128     avs->remaining_audio_size -= size;
 129
 130     if (ret == AVERROR(EIO))
 131         return 0;    /* this indicate EOS */
 132     if (ret < 0)
 133         return ret;
 134
 135     pkt->stream_index = avs->st_audio->index;
 136     pkt->flags |= PKT_FLAG_KEY;
 137
 138     return size;
 139 }
 140
 141 static int avs_read_packet(AVFormatContext * s, AVPacket * pkt)
 142 {
 143     avs_format_t *avs = s->priv_data;
 144     int sub_type = 0, size = 0;
 145     avs_block_type_t type = 0;
 146     int palette_size = 0;
 147     uint8_t palette[4 + 3 * 256];
 148     int ret;
 149
 150     if (avs->remaining_audio_size > 0)
 151         if (avs_read_audio_packet(s, pkt) > 0)
 152             return 0;
 153
 154     while (1) {
 155         if (avs->remaining_frame_size <= 0) {
 156             if (!get_le16(s->pb))    /* found EOF */
 157                 return AVERROR(EIO);
 158             avs->remaining_frame_size = get_le16(s->pb) - 4;
 159         }
 160
 161         while (avs->remaining_frame_size > 0) {
 162             sub_type = get_byte(s->pb);
 163             type = get_byte(s->pb);
 164             size = get_le16(s->pb);
 165             avs->remaining_frame_size -= size;
 166
 167             switch (type) {
 168             case AVS_PALETTE:
 169                 ret = get_buffer(s->pb, palette, size - 4);
 170                 if (ret < size - 4)
 171                     return AVERROR(EIO);
 172                 palette_size = size;
 173                 break;
 174
 175             case AVS_VIDEO:
 176                 if (!avs->st_video) {
 177                     avs->st_video = av_new_stream(s, AVS_VIDEO);
 178                     if (avs->st_video == NULL)
 179                         return AVERROR(ENOMEM);
 180                     avs->st_video->codec->codec_type = CODEC_TYPE_VIDEO;
 181                     avs->st_video->codec->codec_id = CODEC_ID_AVS;
 182                     avs->st_video->codec->width = avs->width;
 183                     avs->st_video->codec->height = avs->height;
 184                     avs->st_video->codec->bits_per_sample=avs->bits_per_sample;
 185                     avs->st_video->nb_frames = avs->nb_frames;
 186                     avs->st_video->codec->time_base = (AVRational) {
 187                     1, avs->fps};
 188                 }
 189                 return avs_read_video_packet(s, pkt, type, sub_type, size,
 190                                              palette, palette_size);
 191
 192             case AVS_AUDIO:
 193                 if (!avs->st_audio) {
 194                     avs->st_audio = av_new_stream(s, AVS_AUDIO);
 195                     if (avs->st_audio == NULL)
 196                         return AVERROR(ENOMEM);
 197                     avs->st_audio->codec->codec_type = CODEC_TYPE_AUDIO;
 198                 }
 199                 avs->remaining_audio_size = size - 4;
 200                 size = avs_read_audio_packet(s, pkt);
 201                 if (size != 0)
 202                     return size;
 203                 break;
 204
 205             default:
 206                 url_fskip(s->pb, size - 4);
 207             }
 208         }
 209     }
 210 }
 211
 212 static int avs_read_close(AVFormatContext * s)
 213 {
 214     return 0;
 215 }
 216
 217 AVInputFormat avs_demuxer = {
 218     "avs",
 219     "avs format",
 220     sizeof(avs_format_t),
 221     avs_probe,
 222     avs_read_header,
 223     avs_read_packet,
 224     avs_read_close,
 225 };