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00022 #include "libavutil/intreadwrite.h"
00023 #include "voc.h"
00024 #include "internal.h"
00025
00026
00027 static int voc_probe(AVProbeData *p)
00028 {
00029 int version, check;
00030
00031 if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
00032 return 0;
00033 version = AV_RL16(p->buf + 22);
00034 check = AV_RL16(p->buf + 24);
00035 if (~version + 0x1234 != check)
00036 return 10;
00037
00038 return AVPROBE_SCORE_MAX;
00039 }
00040
00041 static int voc_read_header(AVFormatContext *s)
00042 {
00043 VocDecContext *voc = s->priv_data;
00044 AVIOContext *pb = s->pb;
00045 int header_size;
00046 AVStream *st;
00047
00048 avio_skip(pb, 20);
00049 header_size = avio_rl16(pb) - 22;
00050 if (header_size != 4) {
00051 av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
00052 return AVERROR(ENOSYS);
00053 }
00054 avio_skip(pb, header_size);
00055 st = avformat_new_stream(s, NULL);
00056 if (!st)
00057 return AVERROR(ENOMEM);
00058 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00059
00060 voc->remaining_size = 0;
00061 return 0;
00062 }
00063
00064 int
00065 ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
00066 {
00067 VocDecContext *voc = s->priv_data;
00068 AVCodecContext *dec = st->codec;
00069 AVIOContext *pb = s->pb;
00070 VocType type;
00071 int size, tmp_codec=-1;
00072 int sample_rate = 0;
00073 int channels = 1;
00074
00075 while (!voc->remaining_size) {
00076 type = avio_r8(pb);
00077 if (type == VOC_TYPE_EOF)
00078 return AVERROR(EIO);
00079 voc->remaining_size = avio_rl24(pb);
00080 if (!voc->remaining_size) {
00081 if (!s->pb->seekable)
00082 return AVERROR(EIO);
00083 voc->remaining_size = avio_size(pb) - avio_tell(pb);
00084 }
00085 max_size -= 4;
00086
00087 switch (type) {
00088 case VOC_TYPE_VOICE_DATA:
00089 if (!dec->sample_rate) {
00090 dec->sample_rate = 1000000 / (256 - avio_r8(pb));
00091 if (sample_rate)
00092 dec->sample_rate = sample_rate;
00093 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
00094 } else
00095 avio_skip(pb, 1);
00096 dec->channels = channels;
00097 tmp_codec = avio_r8(pb);
00098 dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id);
00099 voc->remaining_size -= 2;
00100 max_size -= 2;
00101 channels = 1;
00102 break;
00103
00104 case VOC_TYPE_VOICE_DATA_CONT:
00105 break;
00106
00107 case VOC_TYPE_EXTENDED:
00108 sample_rate = avio_rl16(pb);
00109 avio_r8(pb);
00110 channels = avio_r8(pb) + 1;
00111 sample_rate = 256000000 / (channels * (65536 - sample_rate));
00112 voc->remaining_size = 0;
00113 max_size -= 4;
00114 break;
00115
00116 case VOC_TYPE_NEW_VOICE_DATA:
00117 if (!dec->sample_rate) {
00118 dec->sample_rate = avio_rl32(pb);
00119 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
00120 } else
00121 avio_skip(pb, 4);
00122 dec->bits_per_coded_sample = avio_r8(pb);
00123 dec->channels = avio_r8(pb);
00124 tmp_codec = avio_rl16(pb);
00125 avio_skip(pb, 4);
00126 voc->remaining_size -= 12;
00127 max_size -= 12;
00128 break;
00129
00130 default:
00131 avio_skip(pb, voc->remaining_size);
00132 max_size -= voc->remaining_size;
00133 voc->remaining_size = 0;
00134 break;
00135 }
00136 }
00137
00138 if (tmp_codec >= 0) {
00139 tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
00140 if (dec->codec_id == AV_CODEC_ID_NONE)
00141 dec->codec_id = tmp_codec;
00142 else if (dec->codec_id != tmp_codec)
00143 av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
00144 if (dec->codec_id == AV_CODEC_ID_NONE) {
00145 if (s->audio_codec_id == AV_CODEC_ID_NONE) {
00146 av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
00147 return AVERROR(EINVAL);
00148 }
00149 av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
00150 }
00151 }
00152
00153 dec->bit_rate = dec->sample_rate * dec->channels * dec->bits_per_coded_sample;
00154
00155 if (max_size <= 0)
00156 max_size = 2048;
00157 size = FFMIN(voc->remaining_size, max_size);
00158 voc->remaining_size -= size;
00159 return av_get_packet(pb, pkt, size);
00160 }
00161
00162 static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
00163 {
00164 return ff_voc_get_packet(s, pkt, s->streams[0], 0);
00165 }
00166
00167 AVInputFormat ff_voc_demuxer = {
00168 .name = "voc",
00169 .long_name = NULL_IF_CONFIG_SMALL("Creative Voice"),
00170 .priv_data_size = sizeof(VocDecContext),
00171 .read_probe = voc_probe,
00172 .read_header = voc_read_header,
00173 .read_packet = voc_read_packet,
00174 .codec_tag = (const AVCodecTag* const []){ ff_voc_codec_tags, 0 },
00175 };