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00027 #include "avcodec.h"
00028 #include "internal.h"
00029 #include "get_bits.h"
00030 #include "msgsmdec.h"
00031
00032 #include "gsmdec_template.c"
00033
00034 static av_cold int gsm_init(AVCodecContext *avctx)
00035 {
00036 GSMContext *s = avctx->priv_data;
00037
00038 avctx->channels = 1;
00039 if (!avctx->sample_rate)
00040 avctx->sample_rate = 8000;
00041 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00042
00043 switch (avctx->codec_id) {
00044 case CODEC_ID_GSM:
00045 avctx->frame_size = GSM_FRAME_SIZE;
00046 avctx->block_align = GSM_BLOCK_SIZE;
00047 break;
00048 case CODEC_ID_GSM_MS:
00049 avctx->frame_size = 2 * GSM_FRAME_SIZE;
00050 avctx->block_align = GSM_MS_BLOCK_SIZE;
00051 }
00052
00053 avcodec_get_frame_defaults(&s->frame);
00054 avctx->coded_frame = &s->frame;
00055
00056 return 0;
00057 }
00058
00059 static int gsm_decode_frame(AVCodecContext *avctx, void *data,
00060 int *got_frame_ptr, AVPacket *avpkt)
00061 {
00062 GSMContext *s = avctx->priv_data;
00063 int res;
00064 GetBitContext gb;
00065 const uint8_t *buf = avpkt->data;
00066 int buf_size = avpkt->size;
00067 int16_t *samples;
00068
00069 if (buf_size < avctx->block_align) {
00070 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
00071 return AVERROR_INVALIDDATA;
00072 }
00073
00074
00075 s->frame.nb_samples = avctx->frame_size;
00076 if ((res = ff_get_buffer(avctx, &s->frame)) < 0) {
00077 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00078 return res;
00079 }
00080 samples = (int16_t *)s->frame.data[0];
00081
00082 switch (avctx->codec_id) {
00083 case CODEC_ID_GSM:
00084 init_get_bits(&gb, buf, buf_size * 8);
00085 if (get_bits(&gb, 4) != 0xd)
00086 av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n");
00087 res = gsm_decode_block(avctx, samples, &gb);
00088 if (res < 0)
00089 return res;
00090 break;
00091 case CODEC_ID_GSM_MS:
00092 res = ff_msgsm_decode_block(avctx, samples, buf);
00093 if (res < 0)
00094 return res;
00095 }
00096
00097 *got_frame_ptr = 1;
00098 *(AVFrame *)data = s->frame;
00099
00100 return avctx->block_align;
00101 }
00102
00103 static void gsm_flush(AVCodecContext *avctx)
00104 {
00105 GSMContext *s = avctx->priv_data;
00106 memset(s, 0, sizeof(*s));
00107 }
00108
00109 AVCodec ff_gsm_decoder = {
00110 .name = "gsm",
00111 .type = AVMEDIA_TYPE_AUDIO,
00112 .id = CODEC_ID_GSM,
00113 .priv_data_size = sizeof(GSMContext),
00114 .init = gsm_init,
00115 .decode = gsm_decode_frame,
00116 .flush = gsm_flush,
00117 .capabilities = CODEC_CAP_DR1,
00118 .long_name = NULL_IF_CONFIG_SMALL("GSM"),
00119 };
00120
00121 AVCodec ff_gsm_ms_decoder = {
00122 .name = "gsm_ms",
00123 .type = AVMEDIA_TYPE_AUDIO,
00124 .id = CODEC_ID_GSM_MS,
00125 .priv_data_size = sizeof(GSMContext),
00126 .init = gsm_init,
00127 .decode = gsm_decode_frame,
00128 .flush = gsm_flush,
00129 .capabilities = CODEC_CAP_DR1,
00130 .long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"),
00131 };