tox A/V: encode/decode and display/playback

1 files changed, 823 insertions, 0 deletions

diff --git a/toxmsi/AV_codec.c b/toxmsi/AV_codec.c
new file mode 100644
index 00000000..6730dca9
--- /dev/null
+++ b/toxmsi/AV_codec.c
@@ -0,0 +1,823 @@
+/* AV_codec.c
+//  *
+ * Audio and video codec intitialisation, encoding/decoding and playback
+ *
+ *  Copyright (C) 2013 Tox project All Rights Reserved.
+ *
+ *  This file is part of Tox.
+ *
+ *  Tox is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Tox 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Tox.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/*----------------------------------------------------------------------------------*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif /* HAVE_CONFIG_H */
+
+#include <stdio.h>
+#include <math.h>
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libswscale/swscale.h>
+#include <libavdevice/avdevice.h>
+#include <libavutil/opt.h>
+#include <AL/al.h>
+#include <AL/alc.h>
+#include <SDL.h>
+#include <SDL_thread.h>
+#include <pthread.h>
+#include <opus/opus.h>
+
+#include "toxmsi.h"
+#include "toxmsi_message.h"
+#include "toxrtp_message.h"
+#include "toxrtp/tests/test_helper.h"
+#include "phone.h"
+#include "AV_codec.h"
+
+int display_received_frame(codec_state *cs, AVFrame *r_video_frame)
+{
+    AVPicture pict;
+    SDL_LockYUVOverlay(cs->video_picture.bmp);
+
+    pict.data[0] = cs->video_picture.bmp->pixels[0];
+    pict.data[1] = cs->video_picture.bmp->pixels[2];
+    pict.data[2] = cs->video_picture.bmp->pixels[1];
+    pict.linesize[0] = cs->video_picture.bmp->pitches[0];
+    pict.linesize[1] = cs->video_picture.bmp->pitches[2];
+    pict.linesize[2] = cs->video_picture.bmp->pitches[1];
+
+    /* Convert the image into YUV format that SDL uses */
+    sws_scale(cs->sws_SDL_r_ctx, (uint8_t const * const *)r_video_frame->data, r_video_frame->linesize, 0,
+              cs->video_decoder_ctx->height, pict.data, pict.linesize );
+
+    SDL_UnlockYUVOverlay(cs->video_picture.bmp);
+    SDL_Rect rect;
+    rect.x = 0;
+    rect.y = 0;
+    rect.w = cs->video_decoder_ctx->width;
+    rect.h = cs->video_decoder_ctx->height;
+    SDL_DisplayYUVOverlay(cs->video_picture.bmp, &rect);
+    return 1;
+}
+
+struct jitter_buffer {
+    rtp_msg_t **queue;
+    uint16_t capacity;
+    uint16_t size;
+    uint16_t front;
+    uint16_t rear;
+    uint8_t queue_ready;
+    uint16_t current_id;
+    uint32_t current_ts;
+    uint8_t id_set;
+};
+
+struct jitter_buffer *create_queue(int capacity)
+{
+    struct jitter_buffer *q;
+    q = (struct jitter_buffer *)calloc(sizeof(struct jitter_buffer),1);
+    q->queue = (rtp_msg_t **)calloc((sizeof(rtp_msg_t) * capacity),1);
+    int i = 0;
+
+    for (i = 0; i < capacity; ++i) {
+        q->queue[i] = NULL;
+    }
+
+    q->size = 0;
+    q->capacity = capacity;
+    q->front = 0;
+    q->rear = -1;
+    q->queue_ready = 0;
+    q->current_id = 0;
+    q->current_ts = 0;
+    q->id_set = 0;
+    return q;
+}
+
+/* returns 1 if 'a' has a higher sequence number than 'b' */
+uint8_t sequence_number_older(uint16_t sn_a, uint16_t sn_b, uint32_t ts_a, uint32_t ts_b)
+{
+    /* should be stable enough */
+    return (sn_a > sn_b || ts_a > ts_b);
+}
+
+/* success is 0 when there is nothing to dequeue, 1 when there's a good packet, 2 when there's a lost packet */
+rtp_msg_t *dequeue(struct jitter_buffer *q, int *success)
+{
+    if (q->size == 0 || q->queue_ready == 0) {
+        q->queue_ready = 0;
+        *success = 0;
+        return NULL;
+    }
+
+    int front = q->front;
+
+    if (q->id_set == 0) {
+        q->current_id = q->queue[front]->_header->_sequence_number;
+        q->current_ts = q->queue[front]->_header->_timestamp;
+        q->id_set = 1;
+    } else {
+        int next_id = q->queue[front]->_header->_sequence_number;
+        int next_ts = q->queue[front]->_header->_timestamp;
+
+        /* if this packet is indeed the expected packet */
+        if (next_id == (q->current_id + 1) % _MAX_SEQU_NUM) {
+            q->current_id = next_id;
+            q->current_ts = next_ts;
+        } else {
+            if (sequence_number_older(next_id, q->current_id, next_ts, q->current_ts)) {
+                printf("nextid: %d current: %d\n", next_id, q->current_id);
+                q->current_id = (q->current_id + 1) % _MAX_SEQU_NUM;
+                *success = 2; /* tell the decoder the packet is lost */
+                return NULL;
+            } else {
+                /* packet too old */
+                printf("packet too old\n");
+                *success = 0;
+                return NULL;
+            }
+        }
+    }
+
+    q->size--;
+    q->front++;
+
+    if (q->front == q->capacity)
+        q->front = 0;
+
+    *success = 1;
+    q->current_id = q->queue[front]->_header->_sequence_number;
+    q->current_ts = q->queue[front]->_header->_timestamp;
+    return q->queue[front];
+}
+
+int empty_queue(struct jitter_buffer *q)
+{
+    while (q->size > 0) {
+        q->size--;
+        /* FIXME: */
+        /* rtp_free_msg(cs->_rtp_video, q->queue[q->front]); */
+        q->front++;
+
+        if (q->front == q->capacity)
+            q->front = 0;
+    }
+
+    q->id_set = 0;
+    q->queue_ready = 0;
+    return 0;
+}
+
+int queue(struct jitter_buffer *q, rtp_msg_t *pk)
+{
+    if (q->size == q->capacity) {
+        printf("buffer full, emptying buffer...\n");
+        empty_queue(q);
+        return 0;
+    }
+
+    if (q->size > 8)
+        q->queue_ready = 1;
+
+    ++q->size;
+    ++q->rear;
+
+    if (q->rear == q->capacity)
+        q->rear = 0;
+
+    q->queue[q->rear] = pk;
+
+    int a;
+    int b;
+    int j;
+    a = q->rear;
+
+    for (j = 0; j < q->size - 1; ++j) {
+        b = a - 1;
+
+        if (b < 0)
+            b += q->capacity;
+
+        if (sequence_number_older(q->queue[b]->_header->_sequence_number, q->queue[a]->_header->_sequence_number,
+                                  q->queue[b]->_header->_timestamp, q->queue[a]->_header->_timestamp)) {
+            rtp_msg_t *temp;
+            temp = q->queue[a];
+            q->queue[a] = q->queue[b];
+            q->queue[b] = temp;
+            printf("had to swap\n");
+        } else {
+            break;
+        }
+
+        a -= 1;
+
+        if (a < 0)
+            a += q->capacity;
+    }
+
+    if (pk)
+        return 1;
+
+    return 0;
+}
+
+int init_receive_audio(codec_state *cs)
+{
+    int err = OPUS_OK;
+    cs->audio_decoder = opus_decoder_create(48000, 1, &err);
+    opus_decoder_init(cs->audio_decoder, 48000, 1);
+    printf("init audio decoder successful\n");
+    return 1;
+}
+
+int init_receive_video(codec_state *cs)
+{
+    cs->video_decoder = avcodec_find_decoder(VIDEO_CODEC);
+
+    if (!cs->video_decoder) {
+        printf("init video_decoder failed\n");
+        return 0;
+    }
+
+    cs->video_decoder_ctx = avcodec_alloc_context3(cs->video_decoder);
+
+    if (!cs->video_decoder_ctx) {
+        printf("init video_decoder_ctx failed\n");
+        return 0;
+    }
+
+    if (avcodec_open2(cs->video_decoder_ctx, cs->video_decoder, NULL) < 0) {
+        printf("opening video decoder failed\n");
+        return 0;
+    }
+
+    printf("init video decoder successful\n");
+    return 1;
+}
+
+int init_send_video(codec_state *cs)
+{
+    cs->video_input_format = av_find_input_format(VIDEO_DRIVER);
+
+    if (avformat_open_input(&cs->video_format_ctx, DEFAULT_WEBCAM, cs->video_input_format, NULL) != 0) {
+        printf("opening video_input_format failed\n");
+        return 0;
+    }
+
+    avformat_find_stream_info(cs->video_format_ctx, NULL);
+    av_dump_format(cs->video_format_ctx, 0, DEFAULT_WEBCAM, 0);
+
+    int i;
+
+    for (i = 0; i < cs->video_format_ctx->nb_streams; ++i) {
+        if (cs->video_format_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+            cs->video_stream = i;
+            break;
+        }
+    }
+
+    cs->webcam_decoder_ctx = cs->video_format_ctx->streams[cs->video_stream]->codec;
+    cs->webcam_decoder = avcodec_find_decoder(cs->webcam_decoder_ctx->codec_id);
+
+    if (cs->webcam_decoder == NULL) {
+        printf("Unsupported codec\n");
+        return 0;
+    }
+
+    if (cs->webcam_decoder_ctx == NULL) {
+        printf("init webcam_decoder_ctx failed\n");
+        return 0;
+    }
+
+    if (avcodec_open2(cs->webcam_decoder_ctx, cs->webcam_decoder, NULL) < 0) {
+        printf("opening webcam decoder failed\n");
+        return 0;
+    }
+
+    cs->video_encoder = avcodec_find_encoder(VIDEO_CODEC);
+
+    if (!cs->video_encoder) {
+        printf("init video_encoder failed\n");
+        return 0;
+    }
+
+    cs->video_encoder_ctx = avcodec_alloc_context3(cs->video_encoder);
+
+    if (!cs->video_encoder_ctx) {
+        printf("init video_encoder_ctx failed\n");
+        return 0;
+    }
+
+    cs->video_encoder_ctx->bit_rate = VIDEO_BITRATE;
+    cs->video_encoder_ctx->rc_min_rate = cs->video_encoder_ctx->rc_max_rate = cs->video_encoder_ctx->bit_rate;
+    av_opt_set_double(cs->video_encoder_ctx->priv_data, "max-intra-rate", 90, 0);
+    av_opt_set(cs->video_encoder_ctx->priv_data, "quality", "realtime", 0);
+
+    cs->video_encoder_ctx->thread_count = 4;
+    cs->video_encoder_ctx->rc_buffer_aggressivity = 0.95;
+    cs->video_encoder_ctx->rc_buffer_size = VIDEO_BITRATE * 6;
+    cs->video_encoder_ctx->profile = 3;
+    cs->video_encoder_ctx->qmax = 54;
+    cs->video_encoder_ctx->qmin = 4;
+    AVRational myrational = {1, 25};
+    cs->video_encoder_ctx->time_base = myrational;
+    cs->video_encoder_ctx->gop_size = 99999;
+    cs->video_encoder_ctx->pix_fmt = PIX_FMT_YUV420P;
+    cs->video_encoder_ctx->width = cs->webcam_decoder_ctx->width;
+    cs->video_encoder_ctx->height = cs->webcam_decoder_ctx->height;
+
+    if (avcodec_open2(cs->video_encoder_ctx, cs->video_encoder, NULL) < 0) {
+        printf("opening video encoder failed\n");
+        return 0;
+    }
+
+    printf("init video encoder successful\n");
+    return 1;
+}
+
+int init_send_audio(codec_state *cs)
+{
+    cs->support_send_audio = 0;
+
+    const ALchar *pDeviceList = alcGetString(NULL, ALC_CAPTURE_DEVICE_SPECIFIER);
+    int i = 0;
+    const ALchar *device_names[20];
+
+    if (pDeviceList) {
+        printf("\nAvailable Capture Devices are:\n");
+
+        while (*pDeviceList) {
+            device_names[i] = pDeviceList;
+            printf("%d) %s\n", i, device_names[i]);
+            pDeviceList += strlen(pDeviceList) + 1;
+            ++i;
+        }
+    }
+
+    printf("enter capture device number: \n");
+    char dev[2];
+    fgets(dev, sizeof(dev), stdin);
+    cs->audio_capture_device = alcCaptureOpenDevice(device_names[dev[0] - 48], AUDIO_SAMPLE_RATE, AL_FORMAT_MONO16,
+                               AUDIO_FRAME_SIZE * 4);
+
+    if (alcGetError(cs->audio_capture_device) != AL_NO_ERROR) {
+        printf("could not start capture device! %d\n", alcGetError(cs->audio_capture_device));
+        return 0;
+    }
+
+    int err = OPUS_OK;
+    cs->audio_bitrate = AUDIO_BITRATE;
+    cs->audio_encoder = opus_encoder_create(AUDIO_SAMPLE_RATE, 1, OPUS_APPLICATION_VOIP, &err);
+    err = opus_encoder_ctl(cs->audio_encoder, OPUS_SET_BITRATE(cs->audio_bitrate));
+    err = opus_encoder_ctl(cs->audio_encoder, OPUS_SET_COMPLEXITY(10));
+    err = opus_encoder_ctl(cs->audio_encoder, OPUS_SET_SIGNAL(OPUS_SIGNAL_VOICE));
+
+    opus_encoder_init(cs->audio_encoder, AUDIO_SAMPLE_RATE, 1, OPUS_APPLICATION_VOIP);
+
+    int nfo;
+    err = opus_encoder_ctl(cs->audio_encoder, OPUS_GET_LOOKAHEAD(&nfo));
+    /* printf("Encoder lookahead delay : %d\n", nfo); */
+    printf("init audio encoder successful\n");
+
+    return 1;
+}
+
+int init_encoder(codec_state *cs)
+{
+    avdevice_register_all();
+    avcodec_register_all();
+    avdevice_register_all();
+    av_register_all();
+
+    pthread_mutex_init(&cs->rtp_msg_mutex_lock, NULL);
+    pthread_mutex_init(&cs->avcodec_mutex_lock, NULL);
+
+    cs->support_send_video = init_send_video(cs);
+    cs->support_send_audio = init_send_audio(cs);
+
+    cs->send_audio = 1;
+    cs->send_video = 1;
+
+    return 1;
+}
+
+int init_decoder(codec_state *cs)
+{
+    avdevice_register_all();
+    avcodec_register_all();
+    avdevice_register_all();
+    av_register_all();
+
+    cs->receive_video = 0;
+    cs->receive_audio = 0;
+
+    cs->support_receive_video = init_receive_video(cs);
+    cs->support_receive_audio = init_receive_audio(cs);
+
+    cs->receive_audio = 1;
+    cs->receive_video = 1;
+
+    return 1;
+}
+
+int video_encoder_refresh(codec_state *cs, int bps)
+{
+    if (cs->video_encoder_ctx)
+        avcodec_close(cs->video_encoder_ctx);
+
+    cs->video_encoder = avcodec_find_encoder(VIDEO_CODEC);
+
+    if (!cs->video_encoder) {
+        printf("init video_encoder failed\n");
+        return -1;
+    }
+
+    cs->video_encoder_ctx = avcodec_alloc_context3(cs->video_encoder);
+
+    if (!cs->video_encoder_ctx) {
+        printf("init video_encoder_ctx failed\n");
+        return -1;
+    }
+
+    cs->video_encoder_ctx->bit_rate = bps;
+    cs->video_encoder_ctx->rc_min_rate = cs->video_encoder_ctx->rc_max_rate = cs->video_encoder_ctx->bit_rate;
+    av_opt_set_double(cs->video_encoder_ctx->priv_data, "max-intra-rate", 90, 0);
+    av_opt_set(cs->video_encoder_ctx->priv_data, "quality", "realtime", 0);
+
+    cs->video_encoder_ctx->thread_count = 4;
+    cs->video_encoder_ctx->rc_buffer_aggressivity = 0.95;
+    cs->video_encoder_ctx->rc_buffer_size = bps * 6;
+    cs->video_encoder_ctx->profile = 0;
+    cs->video_encoder_ctx->qmax = 54;
+    cs->video_encoder_ctx->qmin = 4;
+    AVRational myrational = {1, 25};
+    cs->video_encoder_ctx->time_base = myrational;
+    cs->video_encoder_ctx->gop_size = 99999;
+    cs->video_encoder_ctx->pix_fmt = PIX_FMT_YUV420P;
+    cs->video_encoder_ctx->width = cs->webcam_decoder_ctx->width;
+    cs->video_encoder_ctx->height = cs->webcam_decoder_ctx->height;
+
+    if (avcodec_open2(cs->video_encoder_ctx, cs->video_encoder, NULL) < 0) {
+        printf("opening video encoder failed\n");
+        return -1;
+    }
+    return 0;
+}
+
+void *encode_video_thread(void *arg)
+{
+    codec_state *cs = (codec_state *)arg;
+    AVPacket pkt1, *packet = &pkt1;
+    int p = 0;
+    int err;
+    int got_packet;
+    rtp_msg_t *s_video_msg;
+    int video_frame_finished;
+    AVFrame *s_video_frame;
+    AVFrame *webcam_frame;
+    s_video_frame = avcodec_alloc_frame();
+    webcam_frame = avcodec_alloc_frame();
+    AVPacket enc_video_packet;
+
+    uint8_t *buffer;
+    int numBytes;
+    /* Determine required buffer size and allocate buffer */
+    numBytes = avpicture_get_size(PIX_FMT_YUV420P, cs->webcam_decoder_ctx->width, cs->webcam_decoder_ctx->height);
+    buffer = (uint8_t *)av_calloc(numBytes * sizeof(uint8_t),1);
+    avpicture_fill((AVPicture *)s_video_frame, buffer, PIX_FMT_YUV420P, cs->webcam_decoder_ctx->width,
+                   cs->webcam_decoder_ctx->height);
+    cs->sws_ctx = sws_getContext(cs->webcam_decoder_ctx->width, cs->webcam_decoder_ctx->height,
+                                 cs->webcam_decoder_ctx->pix_fmt, cs->webcam_decoder_ctx->width, cs->webcam_decoder_ctx->height, PIX_FMT_YUV420P,
+                                 SWS_BILINEAR, NULL, NULL, NULL);
+
+    while (!cs->quit && cs->send_video) {
+
+        if (av_read_frame(cs->video_format_ctx, packet) < 0) {
+            printf("error reading frame\n");
+
+            if (cs->video_format_ctx->pb->error != 0)
+                break;
+
+            continue;
+        }
+
+        if (packet->stream_index == cs->video_stream) {
+            if (avcodec_decode_video2(cs->webcam_decoder_ctx, webcam_frame, &video_frame_finished, packet) < 0) {
+                printf("couldn't decode\n");
+                continue;
+            }
+
+            av_free_packet(packet);
+            sws_scale(cs->sws_ctx, (uint8_t const * const *)webcam_frame->data, webcam_frame->linesize, 0,
+                      cs->webcam_decoder_ctx->height, s_video_frame->data, s_video_frame->linesize);
+            /* create a new I-frame every 60 frames */
+            ++p;
+
+            if (p == 60) {
+
+                s_video_frame->pict_type = AV_PICTURE_TYPE_BI ;
+            } else if (p == 61) {
+                s_video_frame->pict_type = AV_PICTURE_TYPE_I ;
+                p = 0;
+            } else {
+                s_video_frame->pict_type = AV_PICTURE_TYPE_P ;
+            }
+
+            if (video_frame_finished) {
+                err = avcodec_encode_video2(cs->video_encoder_ctx, &enc_video_packet, s_video_frame, &got_packet);
+
+                if (err < 0) {
+                    printf("could not encode video frame\n");
+                    continue;
+                }
+
+                if (!got_packet) {
+                    continue;
+                }
+
+                pthread_mutex_lock(&cs->rtp_msg_mutex_lock);
+                THREADLOCK()
+
+                if (!enc_video_packet.data) fprintf(stderr, "video packet data is NULL\n");
+
+                s_video_msg = rtp_msg_new ( cs->_rtp_video, enc_video_packet.data, enc_video_packet.size ) ;
+
+                if (!s_video_msg) {
+                    printf("invalid message\n");
+                }
+
+                rtp_send_msg ( cs->_rtp_video, s_video_msg, cs->_networking );
+                THREADUNLOCK()
+                pthread_mutex_unlock(&cs->rtp_msg_mutex_lock);
+                av_free_packet(&enc_video_packet);
+            }
+        } else {
+            av_free_packet(packet);
+        }
+    }
+
+    /* clean up codecs */
+    pthread_mutex_lock(&cs->avcodec_mutex_lock);
+    av_free(buffer);
+    av_free(webcam_frame);
+    av_free(s_video_frame);
+    sws_freeContext(cs->sws_ctx);
+    avcodec_close(cs->webcam_decoder_ctx);
+    avcodec_close(cs->video_encoder_ctx);
+    pthread_mutex_unlock(&cs->avcodec_mutex_lock);
+    pthread_exit ( NULL );
+}
+
+void *encode_audio_thread(void *arg)
+{
+    codec_state *cs = (codec_state *)arg;
+    rtp_msg_t *s_audio_msg;
+    unsigned char encoded_data[4096];
+    int encoded_size = 0;
+    int16_t frame[4096];
+    int frame_size = AUDIO_FRAME_SIZE;
+    ALint sample = 0;
+    alcCaptureStart(cs->audio_capture_device);
+
+    while (!cs->quit && cs->send_audio) {
+        alcGetIntegerv(cs->audio_capture_device, ALC_CAPTURE_SAMPLES, (ALCsizei)sizeof(ALint), &sample);
+
+        if (sample >= frame_size) {
+            alcCaptureSamples(cs->audio_capture_device, frame, frame_size);
+            encoded_size = opus_encode(cs->audio_encoder, frame, frame_size, encoded_data, 480);
+
+            if (encoded_size <= 0) {
+                printf("Could not encode audio packet\n");
+            } else {
+                pthread_mutex_lock(&cs->rtp_msg_mutex_lock);
+                THREADLOCK()
+                rtp_set_payload_type(cs->_rtp_audio, 96);
+                s_audio_msg = rtp_msg_new (cs->_rtp_audio, encoded_data, encoded_size) ;
+                rtp_send_msg ( cs->_rtp_audio, s_audio_msg, cs->_networking );
+                pthread_mutex_unlock(&cs->rtp_msg_mutex_lock);
+                THREADUNLOCK()
+            }
+        } else {
+            usleep(1000);
+        }
+    }
+
+    /* clean up codecs */
+    pthread_mutex_lock(&cs->avcodec_mutex_lock);
+    alcCaptureStop(cs->audio_capture_device);
+    alcCaptureCloseDevice(cs->audio_capture_device);
+
+    pthread_mutex_unlock(&cs->avcodec_mutex_lock);
+    pthread_exit ( NULL );
+}
+
+
+int video_decoder_refresh(codec_state *cs, int width, int height)
+{
+    printf("need to refresh\n");
+    screen = SDL_SetVideoMode(width, height, 0, 0);
+
+    if (cs->video_picture.bmp)
+        SDL_FreeYUVOverlay(cs->video_picture.bmp);
+
+    cs->video_picture.bmp = SDL_CreateYUVOverlay(width, height, SDL_YV12_OVERLAY, screen);
+    cs->sws_SDL_r_ctx = sws_getContext(width, height, cs->video_decoder_ctx->pix_fmt, width, height, PIX_FMT_YUV420P,
+                                       SWS_BILINEAR, NULL, NULL, NULL);
+    return 1;
+}
+
+void *decode_video_thread(void *arg)
+{
+    codec_state *cs = (codec_state *)arg;
+    cs->video_stream = 0;
+    rtp_msg_t *r_msg;
+    int dec_frame_finished;
+    AVFrame *r_video_frame;
+    r_video_frame = avcodec_alloc_frame();
+    AVPacket dec_video_packet;
+    av_new_packet (&dec_video_packet, 65536);
+    int width = 0;
+    int height = 0;
+
+    while (!cs->quit && cs->receive_video) {
+        r_msg = rtp_recv_msg ( cs->_rtp_video );
+
+        if (r_msg) {
+            memcpy(dec_video_packet.data, r_msg->_data, r_msg->_length);
+            dec_video_packet.size = r_msg->_length;
+            avcodec_decode_video2(cs->video_decoder_ctx, r_video_frame, &dec_frame_finished, &dec_video_packet);
+
+            if (dec_frame_finished) {
+                if (cs->video_decoder_ctx->width != width || cs->video_decoder_ctx->height != height) {
+                    width = cs->video_decoder_ctx->width;
+                    height = cs->video_decoder_ctx->height;
+                    printf("w: %d h%d \n", width, height);
+                    video_decoder_refresh(cs, width, height);
+                }
+
+                display_received_frame(cs, r_video_frame);
+            } else {
+                /* TODO: request the sender to create a new i-frame immediatly */
+                printf("bad video packet\n");
+            }
+
+            rtp_free_msg(cs->_rtp_video, r_msg);
+        }
+
+        usleep(1000);
+    }
+
+    printf("vend\n");
+    /* clean up codecs */
+    pthread_mutex_lock(&cs->avcodec_mutex_lock);
+    av_free(r_video_frame);
+    avcodec_close(cs->video_decoder_ctx);
+    pthread_mutex_unlock(&cs->avcodec_mutex_lock);
+    pthread_exit ( NULL );
+}
+
+void *decode_audio_thread(void *arg)
+{
+    codec_state *cs = (codec_state *)arg;
+    rtp_msg_t *r_msg;
+
+    int frame_size = AUDIO_FRAME_SIZE;
+    int data_size;
+
+    ALCdevice *dev;
+    ALCcontext *ctx;
+    ALuint source, *buffers;
+    dev = alcOpenDevice(NULL);
+    ctx = alcCreateContext(dev, NULL);
+    alcMakeContextCurrent(ctx);
+    int openal_buffers = 5;
+
+    buffers = calloc(sizeof(ALuint) * openal_buffers,1);
+    alGenBuffers(openal_buffers, buffers);
+    alGenSources((ALuint)1, &source);
+    alSourcei(source, AL_LOOPING, AL_FALSE);
+
+    ALuint buffer;
+    ALint val;
+
+    ALenum error;
+    uint16_t zeros[frame_size];
+    int i;
+
+    for (i = 0; i < frame_size; i++) {
+        zeros[i] = 0;
+    }
+
+    for (i = 0; i < openal_buffers; ++i) {
+        alBufferData(buffers[i], AL_FORMAT_MONO16, zeros, frame_size, 48000);
+    }
+
+    alSourceQueueBuffers(source, openal_buffers, buffers);
+    alSourcePlay(source);
+
+    if (alGetError() != AL_NO_ERROR) {
+        fprintf(stderr, "Error starting audio\n");
+        cs->quit = 1;
+    }
+
+    struct jitter_buffer *j_buf = NULL;
+
+    j_buf = create_queue(20);
+
+    int success = 0;
+
+    int dec_frame_len;
+
+    opus_int16 PCM[frame_size];
+
+    while (!cs->quit && cs->receive_audio) {
+        THREADLOCK()
+        r_msg = rtp_recv_msg ( cs->_rtp_audio );
+
+        if (r_msg) {
+            /* push the packet into the queue */
+            queue(j_buf, r_msg);
+        }
+
+        /* grab a packet from the queue */
+        success = 0;
+        alGetSourcei(source, AL_BUFFERS_PROCESSED, &val);
+
+        if (val > 0)
+            r_msg = dequeue(j_buf, &success);
+
+        if (success > 0) {
+            /* good packet */
+            if (success == 1) {
+                dec_frame_len = opus_decode(cs->audio_decoder, r_msg->_data, r_msg->_length, PCM, frame_size, 0);
+                rtp_free_msg(cs->_rtp_audio, r_msg);
+            }
+
+            /* lost packet  */
+            if (success == 2) {
+                printf("lost packet\n");
+                dec_frame_len = opus_decode(cs->audio_decoder, NULL, 0, PCM, frame_size, 1);
+            }
+
+            if (dec_frame_len > 0) {
+                alGetSourcei(source, AL_BUFFERS_PROCESSED, &val);
+
+                if (val <= 0)
+                    continue;
+
+                alSourceUnqueueBuffers(source, 1, &buffer);
+                data_size = av_samples_get_buffer_size(NULL, 1, dec_frame_len, AV_SAMPLE_FMT_S16, 1);
+                alBufferData(buffer, AL_FORMAT_MONO16, PCM, data_size, 48000);
+                int error = alGetError();
+
+                if (error != AL_NO_ERROR) {
+                    fprintf(stderr, "Error setting buffer %d\n", error);
+                    break;
+                }
+
+                alSourceQueueBuffers(source, 1, &buffer);
+
+                if (alGetError() != AL_NO_ERROR) {
+                    fprintf(stderr, "error: could not buffer audio\n");
+                    break;
+                }
+
+                alGetSourcei(source, AL_SOURCE_STATE, &val);
+
+                if (val != AL_PLAYING)
+                    alSourcePlay(source);
+
+
+            }
+        }
+
+        THREADUNLOCK()
+        usleep(1000);
+    }
+
+    /* clean up codecs */
+    pthread_mutex_lock(&cs->avcodec_mutex_lock);
+
+    /* clean up openal */
+    alDeleteSources(1, &source);
+    alDeleteBuffers(openal_buffers, buffers);
+    alcMakeContextCurrent(NULL);
+    alcDestroyContext(ctx);
+    alcCloseDevice(dev);
+    pthread_mutex_unlock(&cs->avcodec_mutex_lock);
+    pthread_exit ( NULL );
+}
\ No newline at end of file