initial commit

1 files changed, 154 insertions, 0 deletions

diff --git a/convert.c b/convert.c
new file mode 100644
index 0000000..237f4c1
--- /dev/null
+++ b/convert.c
@@ -0,0 +1,154 @@
+/*
+ * convert.c
+ */
+
+#include "convert.h"
+
+#include <vdr/tools.h>
+
+
+/* --- cConvert ------------------------------------------------------------- */
+
+cConvert::cConvert(const cPostData &postdata)
+{
+        encoder_buf.data = NULL;
+        encoder_buf.length = 0;
+        encoder_open = -1;
+
+        decoder_buf.data = NULL;
+        decoder_buf.length = 0;
+        decoder_open = -1;
+
+        init_decoder();
+        init_encoder(audio_codecs[postdata.get_codec()], postdata.get_bit_rate(),
+                postdata.get_sample_rate(), postdata.get_channels());
+}
+
+
+cConvert::~cConvert()
+{
+        delete[] encoder_buf.data;
+        delete[] decoder_buf.data;
+
+        if (decoder_open > -1) {
+                avcodec_close(decoder_ctx);
+                av_free(decoder_ctx);
+        }
+
+        if (encoder_open > -1) {
+                avcodec_close(encoder_ctx);
+                av_free(encoder_ctx);
+        }
+}
+
+
+void  cConvert::init_decoder(void)
+{
+        decoder_codec = avcodec_find_decoder_by_name("mp2");
+        if (! decoder_codec) {
+                dsyslog("[audiorecorder]: codec mp2 is not supported (%s, "
+                        "%s())", __FILE__,  __func__);
+                return;
+        }
+
+        decoder_ctx = avcodec_alloc_context();
+        decoder_open = avcodec_open(decoder_ctx, decoder_codec);
+
+        if (decoder_open < 0) {
+                dsyslog("[audiorecorder]: could not open codec mp2 (%s, "
+                        "%s())", __FILE__, __func__);
+                return;
+        }
+
+        decoder_buf.data = new uchar[AVCODEC_MAX_AUDIO_FRAME_SIZE];
+
+        dsyslog("[audiorecorder]: decoder initialized (%s, %s())", __FILE__,
+                __func__);
+}
+
+
+void cConvert::init_encoder(const char *codec, int bit_rate, int sample_rate,
+        int channels)
+{
+        encoder_codec = avcodec_find_encoder_by_name(codec);
+        if (! encoder_codec) {
+                dsyslog("[audiorecorder]: codec %s is not supported (%s, "
+                        "%s())", codec, __FILE__,  __func__);
+                return;
+        }
+
+        encoder_ctx = avcodec_alloc_context();
+
+        encoder_ctx->bit_rate = bit_rate;
+        encoder_ctx->sample_rate = sample_rate;
+        encoder_ctx->channels = channels;
+
+        encoder_open = avcodec_open(encoder_ctx, encoder_codec);
+
+        if (encoder_open < 0) {
+                dsyslog("[audiorecorder]: could not open codec %s (%s, %s())", codec, __FILE__, __func__);
+                return;
+        }
+
+        encoder_buf.length = encoder_ctx->frame_size;
+        encoder_buf.data = new uchar[encoder_buf.length];
+
+        dsyslog("[audiorecorder]: encoder for %s-codec (br: %d, sr: %d, %d ch) "
+                "initialized (%s, %s())", encoder_codec->name,
+                encoder_ctx->bit_rate, encoder_ctx->sample_rate,
+                encoder_ctx->channels, __FILE__, __func__);
+}
+
+
+void cConvert::decode_mpa_frame(mpeg_audio_frame *mpa_frame)
+{
+        if (decoder_open < 0) {
+                decoder_buf.length = 0;
+                return;
+        }
+
+#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
+        avcodec_decode_audio(decoder_ctx, (short *)decoder_buf.data,
+                &decoder_buf.length, mpa_frame->data, mpa_frame->length);
+#else
+        decoder_buf.length = AVCODEC_MAX_AUDIO_FRAME_SIZE;
+        avcodec_decode_audio2(decoder_ctx, (short *)decoder_buf.data,
+                &decoder_buf.length, mpa_frame->data, mpa_frame->length);
+#endif
+}
+
+
+abuffer *cConvert::reencode_mpa_frame(mpeg_audio_frame *mpa_frame,
+        float volume)
+{
+        int c, len;
+        short *tmp;
+
+        if (decoder_open < 0 || encoder_open < 0)
+                return &encoder_buf;
+
+        if (strcmp(encoder_codec->name, "mp2") == 0 && volume == 1) {
+                mpa_frame_buf.data = mpa_frame->data;
+                mpa_frame_buf.offset = mpa_frame->length;
+                return &mpa_frame_buf;
+        }
+
+        decode_mpa_frame(mpa_frame);
+
+        if (volume != 1) {
+                /* manipulate the volume */
+                len = decoder_buf.length / sizeof(short);
+                tmp = (short *)decoder_buf.data;
+
+                for (c = 0; c < len; ++c) {
+                        *(tmp) = (short)((float)*(tmp) * volume);
+                        ++tmp;
+                }
+        }
+
+        encoder_buf.offset = avcodec_encode_audio(encoder_ctx, encoder_buf.data,
+                encoder_buf.length, (short *)decoder_buf.data);
+        /* encoder_buf.offset is used to save the size of the encoded frame */
+
+        return &encoder_buf;
+}