+#define STREAM_BUFFER_DURATION 1.5f // 1.5 sec
+#define STREAM_BUFFER_SIZE(format_ptr) (ceil (STREAM_BUFFER_DURATION * ((format_ptr)->speed * (format_ptr)->width * (format_ptr)->channels)))
+
+// We work with 1 sec sequences, so this buffer must be able to contain
+// 1 sec of sound of the highest quality (48 KHz, 16 bit samples, stereo)
+static unsigned char resampling_buffer [48000 * 2 * 2];
+
+
+// Per-sfx data structure
+typedef struct
+{
+ unsigned char *file;
+ size_t filesize;
+ snd_format_t format;
+} ogg_stream_persfx_t;
+
+// Per-channel data structure
+typedef struct
+{
+ OggVorbis_File vf;
+ ov_decode_t ov_decode;
+ int bs;
+ sfxbuffer_t sb; // must be at the end due to its dynamically allocated size
+} ogg_stream_perchannel_t;
+
+
+static const ov_callbacks callbacks = {ovcb_read, ovcb_seek, ovcb_close, ovcb_tell};
+
+/*
+====================
+OGG_FetchSound
+====================
+*/
+static const sfxbuffer_t* OGG_FetchSound (channel_t* ch, unsigned int start, unsigned int nbsamples)
+{
+ ogg_stream_perchannel_t* per_ch;
+ sfxbuffer_t* sb;
+ sfx_t* sfx;
+ snd_format_t* format;
+ ogg_stream_persfx_t* per_sfx;
+ int newlength, done, ret, bigendian;
+ unsigned int factor;
+ size_t buff_len;
+
+ per_ch = (ogg_stream_perchannel_t *)ch->fetcher_data;
+ sfx = ch->sfx;
+ per_sfx = (ogg_stream_persfx_t *)sfx->fetcher_data;
+ format = &sfx->format;
+ buff_len = STREAM_BUFFER_SIZE(format);
+
+ // If there's no fetcher structure attached to the channel yet
+ if (per_ch == NULL)
+ {
+ size_t memsize;
+ ogg_stream_persfx_t* per_sfx;
+
+ memsize = sizeof (*per_ch) - sizeof (per_ch->sb.data) + buff_len;
+ per_ch = (ogg_stream_perchannel_t *)Mem_Alloc (snd_mempool, memsize);
+ sfx->memsize += memsize;
+ per_sfx = (ogg_stream_persfx_t *)sfx->fetcher_data;
+
+ // Open it with the VorbisFile API
+ per_ch->ov_decode.buffer = per_sfx->file;
+ per_ch->ov_decode.ind = 0;
+ per_ch->ov_decode.buffsize = per_sfx->filesize;
+ if (qov_open_callbacks (&per_ch->ov_decode, &per_ch->vf, NULL, 0, callbacks) < 0)
+ {
+ Con_Printf("error while reading Ogg Vorbis stream \"%s\"\n", sfx->name);
+ Mem_Free (per_ch);
+ return NULL;
+ }
+
+ per_ch->sb.offset = 0;
+ per_ch->sb.length = 0;
+ per_ch->bs = 0;
+
+ ch->fetcher_data = per_ch;
+ }
+
+ sb = &per_ch->sb;
+ factor = per_sfx->format.width * per_sfx->format.channels;
+
+ // If the stream buffer can't contain that much samples anyway
+ if (nbsamples * factor > buff_len)
+ {
+ Con_Printf ("OGG_FetchSound: stream buffer too small (%u bytes required)\n", nbsamples * factor);
+ return NULL;
+ }
+
+ // If the data we need has already been decompressed in the sfxbuffer, just return it
+ if (sb->offset <= start && sb->offset + sb->length >= start + nbsamples)
+ return sb;
+
+ newlength = (int)(sb->offset + sb->length) - start;
+
+ // If we need to skip some data before decompressing the rest, or if the stream has looped
+ if (newlength < 0 || sb->offset > start)
+ {
+ if (qov_pcm_seek (&per_ch->vf, (ogg_int64_t)start) != 0)
+ return NULL;
+ sb->length = 0;
+ }
+ // Else, move forward the samples we need to keep in the sfxbuffer
+ else
+ {
+ memmove (sb->data, sb->data + (start - sb->offset) * factor, newlength * factor);
+ sb->length = newlength;
+ }
+
+ sb->offset = start;
+
+ // We add exactly 1 sec of sound to the buffer:
+ // 1- to ensure we won't lose any sample during the resampling process
+ // 2- to force one call to OGG_FetchSound per second to regulate the workload
+ if ((sfx->format.speed + sb->length) * factor > buff_len)
+ {
+ Con_Printf ("OGG_FetchSound: stream buffer overflow (%u bytes / %u)\n",
+ (sfx->format.speed + sb->length) * factor, buff_len);
+ return NULL;
+ }
+ newlength = per_sfx->format.speed * factor; // -> 1 sec of sound before resampling
+
+ // Decompress in the resampling_buffer
+#if BYTE_ORDER == BIG_ENDIAN
+ bigendian = 1;
+#else
+ bigendian = 0;
+#endif
+ done = 0;
+ while ((ret = qov_read (&per_ch->vf, (char *)&resampling_buffer[done], (int)(newlength - done), bigendian, 2, 1, &per_ch->bs)) > 0)
+ done += ret;
+
+ // Resample in the sfxbuffer
+ newlength = (int)ResampleSfx (resampling_buffer, (size_t)done / (size_t)factor, &per_sfx->format, sb->data + sb->length * (size_t)factor, sfx->name);
+ sb->length += newlength;
+
+ return sb;
+}
+
+
+/*
+====================
+OGG_FetchEnd
+====================
+*/
+static void OGG_FetchEnd (channel_t* ch)
+{
+ ogg_stream_perchannel_t* per_ch;
+
+ per_ch = (ogg_stream_perchannel_t *)ch->fetcher_data;
+ if (per_ch != NULL)
+ {
+ size_t buff_len;
+ snd_format_t* format;
+
+ // Free the ogg vorbis decoder
+ qov_clear (&per_ch->vf);
+
+ Mem_Free (per_ch);
+ ch->fetcher_data = NULL;
+
+ format = &ch->sfx->format;
+ buff_len = STREAM_BUFFER_SIZE(format);
+ ch->sfx->memsize -= sizeof (*per_ch) - sizeof (per_ch->sb.data) + buff_len;
+ }
+}
+
+
+/*
+====================
+OGG_FreeSfx
+====================
+*/
+static void OGG_FreeSfx (sfx_t* sfx)
+{
+ ogg_stream_persfx_t* per_sfx = (ogg_stream_persfx_t *)sfx->fetcher_data;
+
+ // Free the Ogg Vorbis file
+ Mem_Free(per_sfx->file);
+ sfx->memsize -= per_sfx->filesize;
+
+ // Free the stream structure
+ Mem_Free(per_sfx);
+ sfx->memsize -= sizeof (*per_sfx);
+
+ sfx->fetcher_data = NULL;
+ sfx->fetcher = NULL;
+}
+
+static const snd_fetcher_t ogg_fetcher = { OGG_FetchSound, OGG_FetchEnd, OGG_FreeSfx };
+
+