--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/decoders/speex.c	Sat Sep 13 20:28:55 2003 +0000
@@ -0,0 +1,436 @@
+/*
+ * SDL_sound -- An abstract sound format decoding API.
+ * Copyright (C) 2001  Ryan C. Gordon.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * Speex decoder for SDL_sound.
+ *
+ * This driver handles Speex audio data. Speex is a codec for speech that is
+ *  meant to be transmitted over narrowband network connections. Epic Games
+ *  estimates that their VoIP solution, built on top of Speex, uses around
+ *  500 bytes per second or less to transmit relatively good sounding speech.
+ *
+ * This decoder processes the .spx files that the speexenc program produces.
+ *
+ * Speex isn't meant for general audio compression. Something like Ogg Vorbis
+ *  will give better results in that case.
+ *
+ * Further Speex information can be found at http://www.speex.org/
+ *
+ * This code is based on speexdec.c (see the Speex website).
+ *
+ * Please see the file COPYING in the source's root directory.
+ *
+ *  This file written by Ryan C. Gordon. (icculus@clutteredmind.org)
+ */
+
+#if HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#ifdef SOUND_SUPPORTS_SPEEX
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <ogg/ogg.h>
+#include <speex.h>
+#include <speex_header.h>
+
+#include "SDL_sound.h"
+
+#define __SDL_SOUND_INTERNAL__
+#include "SDL_sound_internal.h"
+
+static int SPEEX_init(void);
+static void SPEEX_quit(void);
+static int SPEEX_open(Sound_Sample *sample, const char *ext);
+static void SPEEX_close(Sound_Sample *sample);
+static Uint32 SPEEX_read(Sound_Sample *sample);
+static int SPEEX_rewind(Sound_Sample *sample);
+static int SPEEX_seek(Sound_Sample *sample, Uint32 ms);
+
+static const char *extensions_speex[] = { "spx", NULL };
+const Sound_DecoderFunctions __Sound_DecoderFunctions_SPEEX =
+{
+    {
+        extensions_speex,
+        "SPEEX speech compression format",
+        "Ryan C. Gordon <icculus@clutteredmind.org>",
+        "http://www.icculus.org/SDL_sound/"
+    },
+
+    SPEEX_init,       /*   init() method */
+    SPEEX_quit,       /*   quit() method */
+    SPEEX_open,       /*   open() method */
+    SPEEX_close,      /*  close() method */
+    SPEEX_read,       /*   read() method */
+    SPEEX_rewind,     /* rewind() method */
+    SPEEX_seek        /*   seek() method */
+};
+
+#define SPEEX_USE_PERCEPTUAL_ENHANCER 1
+#define SPEEX_MAGIC  0x5367674F  /* "OggS" in ASCII (littleendian) */
+#define SPEEX_OGG_BUFSIZE 200
+
+/* this is what we store in our internal->decoder_private field... */
+typedef struct
+{
+    ogg_sync_state oy;
+    ogg_page og;
+    ogg_packet op;
+    ogg_stream_state os;
+    void *state;
+    SpeexBits bits;
+    int header_count;
+    int frame_size;
+    int nframes;
+    int frames_avail;
+    float *decode_buf;
+    int decode_total;
+    int decode_pos;
+    int have_ogg_packet;
+} speex_t;
+
+
+static int SPEEX_init(void)
+{
+    return(1);   /* no-op. */
+} /* SPEEX_init */
+
+
+static void SPEEX_quit(void)
+{
+    /* no-op. */
+} /* SPEEX_quit */
+
+
+static int process_header(speex_t *speex, Sound_Sample *sample)
+{
+    SpeexMode *mode;
+    SpeexHeader *hptr;
+    SpeexHeader header;
+    int enh_enabled = SPEEX_USE_PERCEPTUAL_ENHANCER;
+    int tmp;
+
+    hptr = speex_packet_to_header((char*) speex->op.packet, speex->op.bytes);
+    BAIL_IF_MACRO(!hptr, "SPEEX: Cannot read header", 0);
+    memcpy(&header, hptr, sizeof (SpeexHeader)); /* move to stack. */
+    free(hptr);  /* lame that this forces you to malloc... */
+
+    BAIL_IF_MACRO(header.mode >= SPEEX_NB_MODES, "SPEEX: Unknown mode", 0);
+    mode = speex_mode_list[header.mode];
+    BAIL_IF_MACRO(header.speex_version_id > 1, "SPEEX: Unknown version", 0);
+    BAIL_IF_MACRO(mode->bitstream_version < header.mode_bitstream_version,
+                  "SPEEX: Unsupported bitstream version", 0);
+    BAIL_IF_MACRO(mode->bitstream_version > header.mode_bitstream_version,
+                  "SPEEX: Unsupported bitstream version", 0);
+
+    speex->state = speex_decoder_init(mode);
+    BAIL_IF_MACRO(!speex->state, "SPEEX: Decoder initialization error", 0);
+
+    speex_decoder_ctl(speex->state, SPEEX_SET_ENH, &enh_enabled);
+    speex_decoder_ctl(speex->state, SPEEX_GET_FRAME_SIZE, &speex->frame_size);
+
+    speex->decode_buf = (float *) malloc(speex->frame_size * sizeof (float));
+    BAIL_IF_MACRO(!speex->decode_buf, ERR_OUT_OF_MEMORY, 0);
+
+    speex->nframes = header.frames_per_packet;
+    if (!speex->nframes)
+        speex->nframes = 1;
+
+    /* !!! FIXME: Write converters to match desired format.
+       !!! FIXME:  We have to convert from Float32 anyhow. */
+    /* !!! FIXME: Is it a performance hit to alter sampling rate?
+       !!! FIXME:  If not, try to match desired rate. */
+    /* !!! FIXME: We force mono output, but speexdec.c has code for stereo.
+       !!! FIXME:  Use that if sample->desired.channels == 2? */
+    tmp = header.rate;
+    speex_decoder_ctl(speex->state, SPEEX_SET_SAMPLING_RATE, &tmp);
+    speex_decoder_ctl(speex->state, SPEEX_GET_SAMPLING_RATE, &tmp);
+    sample->actual.rate = tmp;
+    sample->actual.channels = 1;
+    sample->actual.format = AUDIO_S16SYS;
+
+    SNDDBG(("SPEEX: %dHz, mono, %svbr, %s mode.\n",
+            (int) sample->actual.rate,
+            header.vbr ? "" : "not ",
+            mode->modeName));
+
+    /* plus 2: one for this header, one for the comment header. */
+    speex->header_count = header.extra_headers + 2;
+    return(1);
+} /* process_header */
+
+
+/* !!! FIXME: this code sucks. */
+static int SPEEX_open(Sound_Sample *sample, const char *ext)
+{
+    int set_error_str = 1;
+    int bitstream_initialized = 0;
+    Uint8 *buffer = NULL;
+    int packet_count = 0;
+    speex_t *speex = NULL;
+    Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
+    SDL_RWops *rw = internal->rw;
+    Uint32 magic;
+
+    /* Quick rejection. */
+    /*
+     * !!! FIXME: If (ext) is .spx, ignore bad magic number and assume
+     * !!! FIXME:  this is a corrupted file...try to sync up further in
+     * !!! FIXME:  stream. But for general purposes we can't read the
+     * !!! FIXME:  whole RWops here in case it's not a Speex file at all.
+     */
+    magic = SDL_ReadLE32(rw);  /* make sure this is an ogg stream. */
+    BAIL_IF_MACRO(magic != SPEEX_MAGIC, "SPEEX: Not a complete ogg stream", 0);
+    BAIL_IF_MACRO(SDL_RWseek(rw, -4, SEEK_CUR) < 0, ERR_IO_ERROR, 0);
+
+    speex = (speex_t *) malloc(sizeof (speex_t));
+    BAIL_IF_MACRO(speex == NULL, ERR_OUT_OF_MEMORY, 0);
+    memset(speex, '\0', sizeof (speex_t));
+
+    speex_bits_init(&speex->bits);
+    if (ogg_sync_init(&speex->oy) != 0) goto speex_open_failed;
+
+    while (1)
+    {
+        int rc;
+        Uint8 *buffer = (Uint8*)ogg_sync_buffer(&speex->oy, SPEEX_OGG_BUFSIZE);
+        if (buffer == NULL) goto speex_open_failed;
+        rc = SDL_RWread(rw, buffer, 1, SPEEX_OGG_BUFSIZE);
+        if (rc <= 0) goto speex_open_failed;
+        if (ogg_sync_wrote(&speex->oy, rc) != 0) goto speex_open_failed;
+        while (ogg_sync_pageout(&speex->oy, &speex->og) == 1)
+        {
+            if (!bitstream_initialized)
+            {
+                if (ogg_stream_init(&speex->os, ogg_page_serialno(&speex->og)))
+                    goto speex_open_failed;
+                bitstream_initialized = 1;
+            } /* if */
+
+            if (ogg_stream_pagein(&speex->os, &speex->og) != 0)
+                goto speex_open_failed;
+
+            while (ogg_stream_packetout(&speex->os, &speex->op) == 1)
+            {
+                if (speex->op.e_o_s)
+                    goto speex_open_failed;  /* end of stream already?! */
+
+                packet_count++;
+                if (packet_count == 1)  /* need speex header. */
+                {
+                    if (!process_header(speex, sample))
+                    {
+                        set_error_str = 0; /* process_header will set error string. */
+                        goto speex_open_failed;
+                    } /* if */
+                } /* if */
+
+                if (packet_count > speex->header_count)
+                {
+                    /* if you made it here, you're ready to get a waveform. */
+                    SNDDBG(("SPEEX: Accepting data stream.\n"));
+
+                    /* sample->actual is configured in process_header()... */
+                    speex->have_ogg_packet = 1;
+                    sample->flags = SOUND_SAMPLEFLAG_NONE;
+                    internal->decoder_private = speex;
+                    return(1); /* we'll handle this data. */
+                } /* if */
+            } /* while */
+
+        } /* while */
+
+    } /* while */
+
+    assert(0);  /* shouldn't hit this point. */
+
+speex_open_failed:
+    if (speex != NULL)
+    {
+        if (speex->state != NULL)
+            speex_decoder_destroy(speex->state);
+        if (bitstream_initialized)
+            ogg_stream_clear(&speex->os);
+        speex_bits_destroy(&speex->bits);
+        ogg_sync_clear(&speex->oy);
+        free(speex->decode_buf);
+        free(speex);
+    } /* if */
+
+    if (set_error_str)
+        BAIL_MACRO("SPEEX: decoding error", 0);
+
+    return(0);
+} /* SPEEX_open */
+
+
+static void SPEEX_close(Sound_Sample *sample)
+{
+    Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
+    speex_t *speex = (speex_t *) internal->decoder_private;
+    speex_decoder_destroy(speex->state);
+    ogg_stream_clear(&speex->os);
+    speex_bits_destroy(&speex->bits);
+    ogg_sync_clear(&speex->oy);
+    free(speex->decode_buf);
+    free(speex);
+} /* SPEEX_close */
+
+
+static Uint32 copy_from_decoded(speex_t *speex,
+                                Sound_SampleInternal *internal,
+                                Uint32 _cpypos)
+{
+    /*
+     * !!! FIXME: Obviously, this all needs to change if we allow for
+     * !!! FIXME:  more than mono, S16SYS data.
+     */
+    Uint32 cpypos = _cpypos >> 1;
+    Sint16 *dst = ((Sint16 *) internal->buffer) + cpypos;
+    Sint16 *max;
+    Uint32 maxoutput = (internal->buffer_size >> 1) - cpypos;
+    Uint32 maxavail = speex->decode_total - speex->decode_pos;
+    float *src = speex->decode_buf + speex->decode_pos;
+
+    if (maxavail < maxoutput)
+        maxoutput = maxavail;
+
+    speex->decode_pos += maxoutput;
+    cpypos += maxoutput;
+
+    for (max = dst + maxoutput; dst < max; dst++, src++)
+    {
+        register float f = *src;
+        if (f > 32000.0f)  /* eh, speexdec.c clamps like this, too. */
+            f = 32000.0f;
+        else if (f < -32000.0f)
+            f = -32000.0f;
+        *dst = //(Sint16) round(f);
+               // (Sint16) floor(.5f+f);
+               (Sint16) 0.5f+f;
+    } /* for */
+    
+    return(cpypos << 1);
+} /* copy_from_decoded */
+
+
+/* !!! FIXME: this code sucks. */
+static Uint32 SPEEX_read(Sound_Sample *sample)
+{
+    Uint32 retval = 0;
+    Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
+    speex_t *speex = (speex_t *) internal->decoder_private;
+    SDL_RWops *rw = internal->rw;
+    Uint8 *buffer;
+    int rc;
+
+    while (1)
+    {
+        /* see if there's some already-decoded leftovers... */
+        if (speex->decode_total != speex->decode_pos)
+        {
+            retval = copy_from_decoded(speex, internal, retval);
+            if (retval >= internal->buffer_size)
+                return(retval);  /* whee. */
+        } /* if */
+
+        /* okay, decoded buffer is spent. What else do we have? */
+        speex->decode_total = speex->decode_pos = 0;
+
+        if (speex->frames_avail) /* have more frames to decode? */
+        {
+            rc = speex_decode(speex->state, &speex->bits, speex->decode_buf);
+            if (rc < 0) goto speex_read_failed;
+            if (speex_bits_remaining(&speex->bits) < 0) goto speex_read_failed;
+            speex->frames_avail--;
+            speex->decode_total = speex->frame_size;
+            continue;  /* go fill the output buffer... */
+        } /* if */
+
+        /* need to get more speex frames from available ogg packets... */
+        if (speex->have_ogg_packet)
+        {
+            speex_bits_read_from(&speex->bits,
+                                 (char *) speex->op.packet,
+                                 speex->op.bytes);
+
+            speex->frames_avail += speex->nframes;
+            if (ogg_stream_packetout(&speex->os, &speex->op) <= 0)
+                speex->have_ogg_packet = 0;
+            continue;  /* go decode these frames. */
+        } /* if */
+
+        /* need to get more ogg packets from bitstream... */
+
+        if (speex->op.e_o_s)   /* okay, we're really spent. */
+        {
+            sample->flags |= SOUND_SAMPLEFLAG_EOF;
+            return(retval);
+        } /* if */
+
+        while ((!speex->op.e_o_s) && (!speex->have_ogg_packet))
+        {
+            buffer = (Uint8 *) ogg_sync_buffer(&speex->oy, SPEEX_OGG_BUFSIZE);
+            if (buffer == NULL) goto speex_read_failed;
+            rc = SDL_RWread(rw, buffer, 1, SPEEX_OGG_BUFSIZE);
+            if (rc <= 0) goto speex_read_failed;
+            if (ogg_sync_wrote(&speex->oy, rc) != 0) goto speex_read_failed;
+
+            /* got complete ogg page? */
+            if (ogg_sync_pageout(&speex->oy, &speex->og) == 1)
+            {
+                if (ogg_stream_pagein(&speex->os, &speex->og) != 0)
+                    goto speex_read_failed;
+
+                /* got complete ogg packet? */
+                if (ogg_stream_packetout(&speex->os, &speex->op) == 1)
+                    speex->have_ogg_packet = 1;
+            } /* if */
+        } /* while */
+    } /* while */
+
+    assert(0);  /* never hit this. Either return or goto speex_read_failed */
+
+speex_read_failed:
+    sample->flags |= SOUND_SAMPLEFLAG_ERROR;
+    /* !!! FIXME: "i/o error" is better in some situations. */
+    BAIL_MACRO("SPEEX: Decoding error", retval);
+} /* SPEEX_read */
+
+
+static int SPEEX_rewind(Sound_Sample *sample)
+{
+    /* !!! FIXME */ return(0);
+} /* SPEEX_rewind */
+
+
+static int SPEEX_seek(Sound_Sample *sample, Uint32 ms)
+{
+    /* !!! FIXME */ return(0);
+} /* SPEEX_seek */
+
+
+#endif /* SOUND_SUPPORTS_SPEEX */
+
+/* end of speex.c ... */
+