Initial support for audio in libguac.

src/libguac/Makefile.am

@@ -40,6 +40,7 @@ AM_CFLAGS = -Werror -Wall -pedantic -Iguacamole
 
 libguacincdir = $(includedir)/guacamole
 libguacinc_HEADERS =         \
+    guacamole/audio.h        \
     guacamole/client.h       \
     guacamole/error.h        \
     guacamole/hash.h         \
@@ -55,9 +56,11 @@ libguacinc_HEADERS =         \
 
 noinst_HEADERS =      \
     client-handlers.h \
-    palette.h
+    palette.h         \
+    wav_encoder.h
 
 libguac_la_SOURCES =  \
+    audio.c           \
     client.c          \
     client-handlers.c \
     error.c           \
@@ -73,6 +76,12 @@ libguac_la_SOURCES =  \
     timestamp.c       \
     unicode.c
 
-lib_LTLIBRARIES = libguac.la
+# Compile OGG support if available
-libguac_la_LDFLAGS = -version-info 5:0:0 @PTHREAD_LIBS@ @CAIRO_LIBS@ @PNG_LIBS@ @DL_LIBS@
+if ENABLE_OGG
+libguac_la_SOURCES += ogg_encoder.c
+noinst_HEADERS += ogg_encoder.h
+endif
+
+lib_LTLIBRARIES = libguac.la
+libguac_la_LDFLAGS = -version-info 5:0:0 @PTHREAD_LIBS@ @CAIRO_LIBS@ @PNG_LIBS@ @DL_LIBS@ @VORBIS_LIBS@
 

src/libguac/audio.c

@@ -0,0 +1,174 @@
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is libguac.
+ *
+ * The Initial Developer of the Original Code is
+ * Michael Jumper.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <guacamole/protocol.h>
+#include <guacamole/client.h>
+#include <guacamole/stream.h>
+#include <guacamole/audio.h>
+
+audio_stream* audio_stream_alloc(guac_client* client, audio_encoder* encoder) {
+
+    /* Allocate stream */
+    audio_stream* audio = (audio_stream*) malloc(sizeof(audio_stream));
+    audio->client = client;
+
+    /* Reset buffer stats */
+    audio->used = 0;
+    audio->length = 0x40000;
+
+    audio->encoded_data_used = 0;
+    audio->encoded_data_length = 0x40000;
+
+    /* Allocate buffers */
+    audio->pcm_data = malloc(audio->length);
+    audio->encoded_data = malloc(audio->encoded_data_length);
+
+    /* Assign encoder */
+    audio->encoder = encoder;
+    audio->stream = guac_client_alloc_stream(client);
+
+    /* Ensure socket within new stream is threadsafe */
+    guac_socket_require_threadsafe(audio->stream->socket);
+
+    return audio;
+}
+
+void audio_stream_begin(audio_stream* audio, int rate, int channels, int bps) {
+
+    /* Load PCM properties */
+    audio->rate = rate;
+    audio->channels = channels;
+    audio->bps = bps;
+
+    /* Reset write counter */
+    audio->pcm_bytes_written = 0;
+
+    /* Call handler */
+    audio->encoder->begin_handler(audio);
+
+}
+
+void audio_stream_end(audio_stream* audio) {
+
+    double duration;
+
+    /* Flush stream and finish encoding */
+    audio_stream_flush(audio);
+    audio->encoder->end_handler(audio);
+
+    /* Calculate duration of PCM data */
+    duration = ((double) (audio->pcm_bytes_written * 1000 * 8))
+                / audio->rate / audio->channels / audio->bps;
+
+    /* Send audio */
+    guac_protocol_send_audio(audio->stream->socket,
+            0, audio->encoder->mimetype,
+            duration, audio->encoded_data, audio->encoded_data_used);
+
+    /* Clear data */
+    audio->encoded_data_used = 0;
+
+}
+
+void audio_stream_free(audio_stream* audio) {
+    free(audio->pcm_data);
+    free(audio);
+}
+
+void audio_stream_write_pcm(audio_stream* audio, 
+        unsigned char* data, int length) {
+
+    /* Update counter */
+    audio->pcm_bytes_written += length;
+
+    /* Resize audio buffer if necessary */
+    if (length > audio->length) {
+
+        /* Resize to double provided length */
+        audio->length = length*2;
+        audio->pcm_data = realloc(audio->pcm_data, audio->length);
+
+    }
+
+    /* Flush if necessary */
+    if (audio->used + length > audio->length)
+        audio_stream_flush(audio);
+
+    /* Append to buffer */
+    memcpy(&(audio->pcm_data[audio->used]), data, length);
+    audio->used += length;
+
+}
+
+void audio_stream_flush(audio_stream* audio) {
+
+    /* If data in buffer */
+    if (audio->used != 0) {
+
+        /* Write data */
+        audio->encoder->write_handler(audio,
+                audio->pcm_data, audio->used);
+
+        /* Reset buffer */
+        audio->used = 0;
+
+    }
+
+}
+
+void audio_stream_write_encoded(audio_stream* audio,
+        unsigned char* data, int length) {
+
+    /* Resize audio buffer if necessary */
+    if (audio->encoded_data_used + length > audio->encoded_data_length) {
+
+        /* Increase to double concatenated size to accomodate */
+        audio->encoded_data_length = (audio->encoded_data_length + length)*2;
+        audio->encoded_data = realloc(audio->encoded_data,
+                audio->encoded_data_length);
+
+    }
+
+    /* Append to buffer */
+    memcpy(&(audio->encoded_data[audio->encoded_data_used]), data, length);
+    audio->encoded_data_used += length;
+
+}
+

src/libguac/guacamole/audio.h

@@ -0,0 +1,212 @@
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is libguac.
+ *
+ * The Initial Developer of the Original Code is
+ * Michael Jumper.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef __GUAC_AUDIO_H
+#define __GUAC_AUDIO_H
+
+#include <guacamole/client.h>
+#include <guacamole/stream.h>
+
+typedef struct audio_stream audio_stream;
+
+/**
+ * Handler which is called when the audio stream is opened.
+ */
+typedef void audio_encoder_begin_handler(audio_stream* audio);
+
+/**
+ * Handler which is called when the audio stream is closed.
+ */
+typedef void audio_encoder_end_handler(audio_stream* audio);
+
+/**
+ * Handler which is called when the audio stream is flushed.
+ */
+typedef void audio_encoder_write_handler(audio_stream* audio,
+        unsigned char* pcm_data, int length);
+
+/**
+ * Arbitrary audio codec encoder.
+ */
+typedef struct audio_encoder {
+
+    /**
+     * The mimetype of the audio data encoded by this audio
+     * encoder.
+     */
+    const char* mimetype;
+
+    /**
+     * Handler which will be called when the audio stream is opened.
+     */
+    audio_encoder_begin_handler* begin_handler;
+
+    /**
+     * Handler which will be called when the audio stream is flushed.
+     */
+    audio_encoder_write_handler* write_handler;
+
+    /**
+     * Handler which will be called when the audio stream is closed.
+     */
+    audio_encoder_end_handler* end_handler;
+
+} audio_encoder;
+
+/**
+ * Basic audio stream. PCM data is added to the stream. When the stream is
+ * flushed, a write handler receives PCM data packets and, presumably, streams
+ * them to the guac_stream provided.
+ */
+struct audio_stream {
+
+    /**
+     * PCM data buffer, 16-bit samples, 2-channel, 44100 Hz.
+     */
+    unsigned char* pcm_data;
+
+    /**
+     * Number of bytes in buffer.
+     */
+    int used;
+
+    /**
+     * Maximum number of bytes in buffer.
+     */
+    int length;
+
+    /**
+     * Encoded audio data buffer, as written by the encoder.
+     */
+    unsigned char* encoded_data;
+
+    /**
+     * Number of bytes in the encoded data buffer.
+     */
+    int encoded_data_used;
+
+    /**
+     * Maximum number of bytes in the encoded data buffer.
+     */
+    int encoded_data_length;
+
+    /**
+     * Arbitrary codec encoder. When the PCM buffer is flushed, PCM data will
+     * be sent to this encoder.
+     */
+    audio_encoder* encoder;
+
+    /**
+     * The client associated with this audio stream.
+     */
+    guac_client* client;
+
+    /**
+     * The actual stream associated with this audio stream.
+     */
+    guac_stream* stream;
+
+    /**
+     * The number of samples per second of PCM data sent to this stream.
+     */
+    int rate;
+
+    /**
+     * The number of audio channels per sample of PCM data. Legal values are
+     * 1 or 2.
+     */
+    int channels;
+
+    /**
+     * The number of bits per sample per channel for PCM data. Legal values are
+     * 8 or 16.
+     */
+    int bps;
+
+    /**
+     * The number of PCM bytes written since the audio chunk began.
+     */
+    int pcm_bytes_written;
+
+    /**
+     * Encoder-specific state data.
+     */
+    void* data;
+
+};
+
+/**
+ * Allocates a new audio stream.
+ */
+audio_stream* audio_stream_alloc(guac_client* client,
+        audio_encoder* encoder);
+
+/**
+ * Frees the given audio stream.
+ */
+void audio_stream_free(audio_stream* stream);
+
+/**
+ * Begins a new audio stream.
+ */
+void audio_stream_begin(audio_stream* stream, int rate, int channels, int bps);
+
+/**
+ * Ends the current audio stream.
+ */
+void audio_stream_end(audio_stream* stream);
+
+/**
+ * Writes PCM data to the given audio stream.
+ */
+void audio_stream_write_pcm(audio_stream* stream,
+        unsigned char* data, int length);
+
+/**
+ * Flushes the given audio stream.
+ */
+void audio_stream_flush(audio_stream* stream);
+
+/**
+ * Appends arbitrarily-encoded data to the encoded_data buffer
+ * within the given audio stream.
+ */
+void audio_stream_write_encoded(audio_stream* audio,
+        unsigned char* data, int length);
+
+#endif
+

src/libguac/ogg_encoder.c

@@ -0,0 +1,211 @@
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is libguac.
+ *
+ * The Initial Developer of the Original Code is
+ * Michael Jumper.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include <stdlib.h>
+
+#include <guacamole/audio.h>
+#include <guacamole/client.h>
+#include <guacamole/protocol.h>
+
+#include <vorbis/vorbisenc.h>
+
+#include "ogg_encoder.h"
+
+void ogg_encoder_begin_handler(audio_stream* audio) {
+
+    /* Allocate stream state */
+    ogg_encoder_state* state = (ogg_encoder_state*)
+        malloc(sizeof(ogg_encoder_state));
+
+    /* Init state */
+    vorbis_info_init(&(state->info));
+    vorbis_encode_init_vbr(&(state->info), audio->channels, audio->rate, 0.4);
+
+    vorbis_analysis_init(&(state->vorbis_state), &(state->info));
+    vorbis_block_init(&(state->vorbis_state), &(state->vorbis_block));
+
+    vorbis_comment_init(&(state->comment));
+    vorbis_comment_add_tag(&(state->comment), "ENCODER", "libguac-client-rdp");
+
+    ogg_stream_init(&(state->ogg_state), rand());
+
+    /* Write headers */
+    {
+        ogg_packet header;
+        ogg_packet header_comm;
+        ogg_packet header_code;
+
+        vorbis_analysis_headerout(
+                &(state->vorbis_state),
+                &(state->comment),
+                &header, &header_comm, &header_code);
+
+        ogg_stream_packetin(&(state->ogg_state), &header);
+        ogg_stream_packetin(&(state->ogg_state), &header_comm);
+        ogg_stream_packetin(&(state->ogg_state), &header_code);
+
+        /* For each packet */
+        while (ogg_stream_flush(&(state->ogg_state), &(state->ogg_page)) != 0) {
+
+            /* Write packet header */
+            audio_stream_write_encoded(audio,
+                    state->ogg_page.header,
+                    state->ogg_page.header_len);
+
+            /* Write packet body */
+            audio_stream_write_encoded(audio,
+                    state->ogg_page.body,
+                    state->ogg_page.body_len);
+        }
+
+    }
+
+    audio->data = state;
+
+}
+
+void ogg_encoder_write_blocks(audio_stream* audio) {
+
+    /* Get state */
+    ogg_encoder_state* state = (ogg_encoder_state*) audio->data;
+
+    while (vorbis_analysis_blockout(&(state->vorbis_state),
+                &(state->vorbis_block)) == 1) {
+
+        /* Analyze */
+        vorbis_analysis(&(state->vorbis_block), NULL);
+        vorbis_bitrate_addblock(&(state->vorbis_block));
+
+        /* Flush Ogg pages */
+        while (vorbis_bitrate_flushpacket(&(state->vorbis_state),
+                    &(state->ogg_packet))) {
+
+            /* Weld packet into bitstream */
+            ogg_stream_packetin(&(state->ogg_state), &(state->ogg_packet));
+
+            /* Write out pages */
+            while (ogg_stream_pageout(&(state->ogg_state),
+                        &(state->ogg_page)) != 0) {
+
+                /* Write packet header */
+                audio_stream_write_encoded(audio,
+                        state->ogg_page.header,
+                        state->ogg_page.header_len);
+
+                /* Write packet body */
+                audio_stream_write_encoded(audio,
+                        state->ogg_page.body,
+                        state->ogg_page.body_len);
+
+                if (ogg_page_eos(&(state->ogg_page)))
+                    break;
+
+            }
+
+        }
+
+    }
+
+}
+
+void ogg_encoder_end_handler(audio_stream* audio) {
+
+    /* Get state */
+    ogg_encoder_state* state = (ogg_encoder_state*) audio->data;
+
+    /* Write end-of-stream */
+    vorbis_analysis_wrote(&(state->vorbis_state), 0);
+    ogg_encoder_write_blocks(audio);
+
+    /* Clean up encoder */
+    ogg_stream_clear(&(state->ogg_state));
+    vorbis_block_clear(&(state->vorbis_block));
+    vorbis_dsp_clear(&(state->vorbis_state));
+    vorbis_comment_clear(&(state->comment));
+    vorbis_info_clear(&(state->info));
+
+    /* Free stream state */
+    free(audio->data);
+
+}
+
+void ogg_encoder_write_handler(audio_stream* audio, 
+        unsigned char* pcm_data, int length) {
+
+    /* Get state */
+    ogg_encoder_state* state = (ogg_encoder_state*) audio->data;
+
+    /* Calculate samples */
+    int samples = length / audio->channels * 8 / audio->bps;
+    int i;
+
+    /* Get buffer */
+    float** buffer = vorbis_analysis_buffer(&(state->vorbis_state), samples);
+
+    signed char* readbuffer = (signed char*) pcm_data;
+
+    for (i=0; i<samples; i++) {
+
+        /* FIXME: For now, assume 2 channels, 16-bit */
+        int left  = ((readbuffer[i*4+1]<<8)|(0x00ff&(int)readbuffer[i*4]));
+        int right = ((readbuffer[i*4+3]<<8)|(0x00ff&(int)readbuffer[i*4+2]));
+
+        /* Store sample in buffer */
+        buffer[0][i] = left  / 32768.f;
+        buffer[1][i] = right / 32768.f;
+
+    }
+
+    /* Submit data */
+    vorbis_analysis_wrote(&(state->vorbis_state), samples);
+
+    /* Write data */
+    ogg_encoder_write_blocks(audio);
+
+}
+
+/* Encoder handlers */
+audio_encoder _ogg_encoder = {
+    .mimetype      = "audio/ogg",
+    .begin_handler = ogg_encoder_begin_handler,
+    .write_handler = ogg_encoder_write_handler,
+    .end_handler   = ogg_encoder_end_handler
+};
+
+/* Actual encoder */
+audio_encoder* ogg_encoder = &_ogg_encoder;
+

src/libguac/ogg_encoder.h

@@ -0,0 +1,67 @@
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is libguac.
+ *
+ * The Initial Developer of the Original Code is
+ * Michael Jumper.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef __GUAC_OGG_ENCODER_H
+#define __GUAC_OGG_ENCODER_H
+
+#include <guacamole/audio.h>
+
+#include <vorbis/vorbisenc.h>
+
+typedef struct ogg_encoder_state {
+
+    /**
+     * Ogg state
+     */
+    ogg_stream_state ogg_state;
+    ogg_page ogg_page;
+    ogg_packet ogg_packet;
+
+    /**
+     * Vorbis state
+     */
+    vorbis_info info;
+    vorbis_comment comment;
+    vorbis_dsp_state vorbis_state;
+    vorbis_block vorbis_block;
+
+} ogg_encoder_state;
+
+extern audio_encoder* ogg_encoder;
+
+#endif
+

src/libguac/wav_encoder.c

@@ -0,0 +1,201 @@
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is libguac.
+ *
+ * The Initial Developer of the Original Code is
+ * Michael Jumper.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#define WAV_BUFFER_SIZE 0x4000
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <guacamole/audio.h>
+#include <guacamole/client.h>
+#include <guacamole/protocol.h>
+
+#include "wav_encoder.h"
+
+void wav_encoder_begin_handler(audio_stream* audio) {
+
+    /* Allocate stream state */
+    wav_encoder_state* state = (wav_encoder_state*)
+        malloc(sizeof(wav_encoder_state));
+
+    /* Initialize buffer */
+    state->length = WAV_BUFFER_SIZE;
+    state->used = 0;
+    state->data_buffer = (unsigned char*) malloc(state->length);
+
+    audio->data = state;
+
+}
+
+void _wav_encoder_write_le(unsigned char* buffer, int value, int length) {
+
+    int offset;
+
+    /* Write all bytes in the given value in little-endian byte order */
+    for (offset=0; offset<length; offset++) {
+
+        /* Store byte */
+        *buffer = value & 0xFF;
+
+        /* Move to next byte */
+        value >>= 8;
+        buffer++;
+
+    }
+
+}
+
+void wav_encoder_end_handler(audio_stream* audio) {
+
+    /*
+     * Static header init
+     */
+
+    wav_encoder_riff_header riff_header = {
+        .chunk_id     = "RIFF",
+        .chunk_format = "WAVE"
+    };
+
+    wav_encoder_fmt_header fmt_header = {
+        .subchunk_id     = "fmt ",
+        .subchunk_size   = {0x10, 0x00, 0x00, 0x00}, /* 16 */
+        .subchunk_format = {0x01, 0x00}              /* 1 = PCM */
+    };
+
+    wav_encoder_data_header data_header = {
+        .subchunk_id = "data"
+    };
+
+    /* Get state */
+    wav_encoder_state* state = (wav_encoder_state*) audio->data;
+
+    /*
+     * RIFF HEADER
+     */
+
+    /* Chunk size */
+    _wav_encoder_write_le(riff_header.chunk_size,
+            4 + sizeof(fmt_header) + sizeof(data_header) + state->used,
+            sizeof(riff_header.chunk_size));
+
+    audio_stream_write_encoded(audio,
+            (unsigned char*) &riff_header,
+            sizeof(riff_header));
+
+    /*
+     * FMT HEADER
+     */
+
+    /* Channels */
+    _wav_encoder_write_le(fmt_header.subchunk_channels,
+            audio->channels, sizeof(fmt_header.subchunk_channels));
+
+    /* Sample rate */
+    _wav_encoder_write_le(fmt_header.subchunk_sample_rate,
+            audio->rate, sizeof(fmt_header.subchunk_sample_rate));
+
+    /* Byte rate */
+    _wav_encoder_write_le(fmt_header.subchunk_byte_rate,
+            audio->rate * audio->channels * audio->bps / 8,
+            sizeof(fmt_header.subchunk_byte_rate));
+
+    /* Block align */
+    _wav_encoder_write_le(fmt_header.subchunk_block_align,
+            audio->channels * audio->bps / 8,
+            sizeof(fmt_header.subchunk_block_align));
+
+    /* Bits per second */
+    _wav_encoder_write_le(fmt_header.subchunk_bps,
+            audio->bps, sizeof(fmt_header.subchunk_bps));
+
+    audio_stream_write_encoded(audio,
+            (unsigned char*) &fmt_header,
+            sizeof(fmt_header));
+
+    /*
+     * DATA HEADER
+     */
+
+    /* PCM data size */
+    _wav_encoder_write_le(data_header.subchunk_size,
+            state->used, sizeof(data_header.subchunk_size));
+
+    audio_stream_write_encoded(audio,
+            (unsigned char*) &data_header,
+            sizeof(data_header));
+
+    /* Write .wav data */
+    audio_stream_write_encoded(audio, state->data_buffer, state->used);
+
+    /* Free stream state */
+    free(state);
+
+}
+
+void wav_encoder_write_handler(audio_stream* audio, 
+        unsigned char* pcm_data, int length) {
+
+    /* Get state */
+    wav_encoder_state* state = (wav_encoder_state*) audio->data;
+
+    /* Increase size of buffer if necessary */
+    if (state->used + length > state->length) {
+
+        /* Increase to double concatenated size to accomodate */
+        state->length = (state->length + length)*2;
+        state->data_buffer = realloc(state->data_buffer,
+                state->length);
+
+    }
+
+    /* Append to buffer */
+    memcpy(&(state->data_buffer[state->used]), pcm_data, length);
+    state->used += length;
+
+}
+
+/* Encoder handlers */
+audio_encoder _wav_encoder = {
+    .mimetype      = "audio/wav",
+    .begin_handler = wav_encoder_begin_handler,
+    .write_handler = wav_encoder_write_handler,
+    .end_handler   = wav_encoder_end_handler
+};
+
+/* Actual encoder */
+audio_encoder* wav_encoder = &_wav_encoder;
+

src/libguac/wav_encoder.h

@@ -0,0 +1,144 @@
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is libguac.
+ *
+ * The Initial Developer of the Original Code is
+ * Michael Jumper.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef __GUAC_WAV_ENCODER_H
+#define __GUAC_WAV_ENCODER_H
+
+#include <guacamole/audio.h>
+
+typedef struct wav_encoder_riff_header {
+
+    /**
+     * The RIFF chunk header, normally the string "RIFF".
+     */
+    unsigned char chunk_id[4];
+
+    /**
+     * Size of the entire file, not including chunk_id or chunk_size.
+     */
+    unsigned char chunk_size[4];
+
+    /**
+     * The format of this file, normally the string "WAVE".
+     */
+    unsigned char chunk_format[4];
+
+} wav_encoder_riff_header;
+
+typedef struct wav_encoder_fmt_header {
+
+    /**
+     * ID of this subchunk. For the fmt subchunk, this should be "fmt ".
+     */
+    unsigned char subchunk_id[4];
+
+    /**
+     * The size of the rest of this subchunk. For PCM, this will be 16.
+     */
+    unsigned char subchunk_size[4];
+
+    /**
+     * Format of this subchunk. For PCM, this will be 1.
+     */
+    unsigned char subchunk_format[2];
+
+    /**
+     * The number of channels in the PCM data.
+     */
+    unsigned char subchunk_channels[2];
+
+    /**
+     * The sample rate of the PCM data.
+     */
+    unsigned char subchunk_sample_rate[4];
+
+    /**
+     * The sample rate of the PCM data in bytes per second.
+     */
+    unsigned char subchunk_byte_rate[4];
+
+    /**
+     * The number of bytes per sample.
+     */
+    unsigned char subchunk_block_align[2];
+
+    /**
+     * The number of bits per sample.
+     */
+    unsigned char subchunk_bps[2];
+
+} wav_encoder_fmt_header;
+
+typedef struct wav_encoder_state {
+
+    /**
+     * Arbitrary PCM data available for writing when the overall WAV is
+     * flushed.
+     */
+    unsigned char* data_buffer;
+
+    /**
+     * The number of bytes currently present in the data buffer.
+     */
+    int used;
+
+    /**
+     * The total number of bytes that can be written into the data buffer
+     * without requiring resizing.
+     */
+    int length;
+
+} wav_encoder_state;
+
+typedef struct wav_encoder_data_header {
+
+    /**
+     * ID of this subchunk. For the data subchunk, this should be "data".
+     */
+    unsigned char subchunk_id[4];
+
+    /**
+     * The number of bytes in the PCM data.
+     */
+    unsigned char subchunk_size[4];
+
+} wav_encoder_data_header;
+
+extern audio_encoder* wav_encoder;
+
+#endif
+