plugins/codecs/iLBC/iLBCdecode.c

   1 /* iLBCdecode.c
   2  * iLBC codec
   3  *
   4  * Wireshark - Network traffic analyzer
   5  * By Gerald Combs <gerald@wireshark.org>
   6  * Copyright 1998 Gerald Combs
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 #include "config.h"
  12
  13 #include <stdio.h>
  14
  15 #include <glib.h>
  16
  17 #include "ilbc.h"
  18 #include "wsutil/codecs.h"
  19 #include "ws_attributes.h"
  20
  21 #define ILBC_20MS 20
  22 #define ILBC_30MS 30
  23 #define ILBC_PAYLOAD_LEN_20MS 38
  24 #define ILBC_PAYLOAD_LEN_30MS 50
  25 #define SAMPLE_SIZE 2
  26
  27 typedef struct {
  28 #ifdef LIBILBC_VERSION_MAJOR
  29     IlbcDecoderInstance *ilbc_ctx;  /* Real iLBC context */
  30 #else
  31     iLBC_decinst_t *ilbc_ctx;  /* Real iLBC context */
  32 #endif
  33     uint8_t payload_len; /* Remember last payload_len */
  34 } ilbc_ctx_t;
  35
  36 void codec_register_iLBC(void);
  37
  38 static void *
  39 codec_iLBC_init(codec_context_t *ctx _U_)
  40 {
  41     ilbc_ctx_t *priv;
  42
  43     priv=(ilbc_ctx_t *)g_malloc0(sizeof(*priv));
  44     WebRtcIlbcfix_DecoderCreate(&(priv->ilbc_ctx));
  45
  46     return priv;
  47 }
  48
  49 static void
  50 codec_iLBC_release(codec_context_t *ctx)
  51 {
  52     WebRtcIlbcfix_DecoderFree(((ilbc_ctx_t *)ctx->priv)->ilbc_ctx);
  53     g_free(ctx);
  54 }
  55
  56 static unsigned
  57 codec_iLBC_get_channels(codec_context_t *ctx _U_)
  58 {
  59     return 1;
  60 }
  61
  62 static unsigned
  63 codec_iLBC_get_frequency(codec_context_t *ctx _U_)
  64 {
  65     return 8000;
  66 }
  67
  68 static size_t
  69 codec_iLBC_decode(codec_context_t *ctx,
  70         const void *inputBytes, size_t inputBytesSize,
  71         void *outputSamples, size_t *outputSamplesSize)
  72 {
  73     int16_t speechType; // Not used in Wireshark code
  74 #ifdef LIBILBC_VERSION_MAJOR
  75     int8_t *dataIn  = (int8_t *)inputBytes;
  76 #else
  77     int16_t *dataIn  = (int16_t *)inputBytes;
  78 #endif
  79     int16_t *dataOut = (int16_t *)outputSamples;
  80     ilbc_ctx_t *dataCtx = (ilbc_ctx_t *)ctx->priv;
  81     size_t outputSamplesCount;
  82
  83     if (!outputSamples || !outputSamplesSize)
  84     {
  85         if (0 == inputBytesSize%ILBC_PAYLOAD_LEN_20MS) {
  86             /* 20ms packet size = 160 samples = 320 bytes */
  87             return BLOCKL_20MS*SAMPLE_SIZE;
  88         } else if (0 == inputBytesSize%ILBC_PAYLOAD_LEN_30MS) {
  89             /* 30ms packet size = 240 samples = 480 bytes */
  90             return BLOCKL_30MS*SAMPLE_SIZE;
  91         } else {
  92             /* unknown packet size */
  93             return 0;
  94         }
  95     }
  96
  97     if (0 == inputBytesSize%ILBC_PAYLOAD_LEN_20MS) {
  98         /* 20ms packet size */
  99         if (dataCtx->payload_len != ILBC_20MS) {
 100             WebRtcIlbcfix_DecoderInit(dataCtx->ilbc_ctx, ILBC_20MS);
 101             dataCtx->payload_len = ILBC_20MS;
 102         }
 103         outputSamplesCount = WebRtcIlbcfix_Decode(dataCtx->ilbc_ctx, dataIn,
 104                                (int16_t)inputBytesSize, dataOut, &speechType);
 105     } else if (0 == inputBytesSize%ILBC_PAYLOAD_LEN_30MS) {
 106         /* 30ms packet size */
 107         if (dataCtx->payload_len != ILBC_30MS) {
 108             WebRtcIlbcfix_DecoderInit(dataCtx->ilbc_ctx, ILBC_30MS);
 109             dataCtx->payload_len = ILBC_30MS;
 110         }
 111         outputSamplesCount = WebRtcIlbcfix_Decode(dataCtx->ilbc_ctx, dataIn,
 112                                (int16_t)inputBytesSize, dataOut, &speechType);
 113     } else {
 114         /* unknown packet size */
 115         outputSamplesCount = 0;
 116     }
 117
 118     /* WebRtcIlbcfix_Decode returns count of samples, but we return count of bytes */
 119     *outputSamplesSize = outputSamplesCount*SAMPLE_SIZE;
 120     return *outputSamplesSize;
 121 }
 122
 123 void
 124 codec_register_iLBC(void)
 125 {
 126     register_codec("iLBC", codec_iLBC_init, codec_iLBC_release,
 127             codec_iLBC_get_channels, codec_iLBC_get_frequency, codec_iLBC_decode);
 128 }
 129
 130 /*
 131  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 132  *
 133  * Local variables:
 134  * c-basic-offset: 4
 135  * tab-width: 8
 136  * indent-tabs-mode: nil
 137  * End:
 138  *
 139  * vi: set shiftwidth=4 tabstop=8 expandtab:
 140  * :indentSize=4:tabSize=8:noTabs=true:
 141  */