shithub: libopusenc

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Fixes LPC extension for the resampling case

We have to do the extension at the input sampling rate, not at the output
sampling rate.

--- a/examples/opusenc_example.c

+++ b/examples/opusenc_example.c

@@ -20,7 +20,7 @@

   comments = ope_comments_create();

   ope_comments_add(comments, "ARTIST", "Someone");

   ope_comments_add(comments, "TITLE", "Some track");

-  enc = ope_encoder_create_file(argv[2], comments, 48000, 2, 0, &error);

+  enc = ope_encoder_create_file(argv[2], comments, 44100, 2, 0, &error);

   if (!enc) {

     fprintf(stderr, "cannout open output file: %s\n", argv[2]);

     fclose(fin);

--- a/src/opusenc.c

+++ b/src/opusenc.c

@@ -176,6 +176,7 @@

   opus_int64 curr_granule;

   opus_int64 write_granule;

   opus_int64 last_page_granule;

+  float *lpc_buffer;

   unsigned char *chaining_keyframe;

   int chaining_keyframe_length;

   OpusEncCallbacks callbacks;

@@ -328,6 +329,13 @@

   enc->write_granule = 0;

   enc->last_page_granule = 0;

   if ( (enc->buffer = malloc(sizeof(*enc->buffer)*BUFFER_SAMPLES*channels)) == NULL) goto fail;

+  if (rate != 48000) {

+    /* Allocate an extra LPC_PADDING samples so we can do the padding in-place. */

+    if ( (enc->lpc_buffer = malloc(sizeof(*enc->lpc_buffer)*(LPC_INPUT+LPC_PADDING)*channels)) == NULL) goto fail;

+    memset(enc->lpc_buffer, 0, sizeof(*enc->lpc_buffer)*LPC_INPUT*channels);

+  } else {

+    enc->lpc_buffer = NULL;

+  }

   enc->buffer_start = enc->buffer_end = 0;

   enc->st = st;

   enc->callbacks = *callbacks;

@@ -339,6 +347,7 @@

     free(enc);

     if (enc->buffer) free(enc->buffer);

     if (enc->streams) stream_destroy(enc->streams);

+    if (enc->lpc_buffer) free(enc->lpc_buffer);

   }

   if (st) {

     opus_multistream_encoder_destroy(st);

@@ -515,6 +524,15 @@

   if (samples_per_channel < 0) return OPE_BAD_ARG;

   enc->write_granule += samples_per_channel;

   enc->last_stream->end_granule = enc->write_granule;

+  if (enc->lpc_buffer) {

+    int i;

+    if (samples_per_channel < LPC_INPUT) {

+      for (i=0;i<(LPC_INPUT-samples_per_channel)*channels;i++) enc->lpc_buffer[i] = enc->lpc_buffer[samples_per_channel*channels + i];

+      for (i=0;i<samples_per_channel*channels;i++) enc->lpc_buffer[(LPC_INPUT-samples_per_channel)*channels] = pcm[i];

+    } else {

+      for (i=0;i<LPC_INPUT*channels;i++) enc->lpc_buffer[i] = pcm[(samples_per_channel-LPC_INPUT)*channels + i];

+    }

+  }

   do {

     int i;

     spx_uint32_t in_samples, out_samples;

@@ -550,6 +568,15 @@

   if (samples_per_channel < 0) return OPE_BAD_ARG;

   enc->write_granule += samples_per_channel;

   enc->last_stream->end_granule = enc->write_granule;

+  if (enc->lpc_buffer) {

+    int i;

+    if (samples_per_channel < LPC_INPUT) {

+      for (i=0;i<(LPC_INPUT-samples_per_channel)*channels;i++) enc->lpc_buffer[i] = enc->lpc_buffer[samples_per_channel*channels + i];

+      for (i=0;i<samples_per_channel*channels;i++) enc->lpc_buffer[(LPC_INPUT-samples_per_channel)*channels + i] = (1.f/32768)*pcm[i];

+    } else {

+      for (i=0;i<LPC_INPUT*channels;i++) enc->lpc_buffer[i] = (1.f/32768)*pcm[(samples_per_channel-LPC_INPUT)*channels + i];

+    }

+  }

   do {

     int i;

     spx_uint32_t in_samples, out_samples;

@@ -592,17 +619,33 @@

 int ope_encoder_drain(OggOpusEnc *enc) {

   int pad_samples;

+  int resampler_drain = 0;

   if (enc->unrecoverable) return OPE_UNRECOVERABLE;

   /* Check if it's already been drained. */

   if (enc->streams == NULL) return OPE_TOO_LATE;

-  pad_samples = MAX(LPC_PADDING, enc->global_granule_offset + enc->frame_size);

+  if (enc->re) resampler_drain = speex_resampler_get_output_latency(enc->re);

+  pad_samples = MAX(LPC_PADDING, enc->global_granule_offset + enc->frame_size + resampler_drain);

   if (!enc->streams->stream_is_init) init_stream(enc);

   shift_buffer(enc);

   assert(enc->buffer_end + pad_samples <= BUFFER_SAMPLES);

   memset(&enc->buffer[enc->channels*enc->buffer_end], 0, pad_samples*enc->channels*sizeof(enc->buffer[0]));

-  extend_signal(&enc->buffer[enc->channels*enc->buffer_end], enc->buffer_end, LPC_PADDING, enc->channels);

+  if (enc->re) {

+    spx_uint32_t in_samples, out_samples;

+    extend_signal(&enc->lpc_buffer[LPC_INPUT*enc->channels], LPC_INPUT, LPC_PADDING, enc->channels);

+    do {

+      in_samples = LPC_PADDING;

+      out_samples = pad_samples;

+      speex_resampler_process_interleaved_float(enc->re, &enc->lpc_buffer[LPC_INPUT*enc->channels], &in_samples, &enc->buffer[enc->channels*enc->buffer_end], &out_samples);

+      enc->buffer_end += out_samples;

+      pad_samples -= out_samples;

+      /* If we don't have enough padding, zero all zeros and repeat. */

+      memset(&enc->lpc_buffer[LPC_INPUT*enc->channels], 0, LPC_PADDING*enc->channels*sizeof(enc->lpc_buffer[0]));

+    } while (pad_samples > 0);

+  } else {

+    extend_signal(&enc->buffer[enc->channels*enc->buffer_end], enc->buffer_end, LPC_PADDING, enc->channels);

+    enc->buffer_end += pad_samples;

+  }

   enc->decision_delay = 0;

-  enc->buffer_end += pad_samples;

   assert(enc->buffer_end <= BUFFER_SAMPLES);

   encode_buffer(enc);

   if (enc->unrecoverable) return OPE_UNRECOVERABLE;

@@ -625,6 +668,7 @@

   if (enc->oggp) oggp_destroy(enc->oggp);

   opus_multistream_encoder_destroy(enc->st);

   if (enc->re) speex_resampler_destroy(enc->re);

+  if (enc->lpc_buffer) free(enc->lpc_buffer);

   free(enc);

 }