Add audio support for the DeckLink inputs.

[nageru] / mixer.cpp

diff --git a/mixer.cpp b/mixer.cpp
index e8c9a758ad4f6c25bd6fb144cc565c1234ff7999..d725ad36b8fe84415d1b92f6201510b978029f2d 100644 (file)
--- a/mixer.cpp
+++ b/mixer.cpp
@@ -50,6 +50,7 @@ namespace {
 
 void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
 {
+       assert(in_channels >= out_channels);
        for (size_t i = 0; i < num_samples; ++i) {
                for (size_t j = 0; j < out_channels; ++j) {
                        uint32_t s1 = *src++;
@@ -62,6 +63,20 @@ void convert_fixed24_to_fp32(float *dst, size_t out_channels, const uint8_t *src
        }
 }
 
+void convert_fixed32_to_fp32(float *dst, size_t out_channels, const uint8_t *src, size_t in_channels, size_t num_samples)
+{
+       assert(in_channels >= out_channels);
+       for (size_t i = 0; i < num_samples; ++i) {
+               for (size_t j = 0; j < out_channels; ++j) {
+                       // Note: Assumes little-endian.
+                       int32_t s = *(int32_t *)src;
+                       dst[i * out_channels + j] = s * (1.0f / 4294967296.0f);
+                       src += 4;
+               }
+               src += 4 * (in_channels - out_channels);
+       }
+}
+
 void insert_new_frame(RefCountedFrame frame, unsigned field_num, bool interlaced, unsigned card_index, InputState *input_state)
 {
        if (interlaced) {
@@ -316,7 +331,7 @@ void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 
        int64_t frame_length = int64_t(TIMEBASE * video_format.frame_rate_den) / video_format.frame_rate_nom;
 
-       size_t num_samples = (audio_frame.len >= audio_offset) ? (audio_frame.len - audio_offset) / 8 / 3 : 0;
+       size_t num_samples = (audio_frame.len >= audio_offset) ? (audio_frame.len - audio_offset) / audio_format.num_channels / (audio_format.bits_per_sample / 8) : 0;
        if (num_samples > OUTPUT_FREQUENCY / 10) {
                printf("Card %d: Dropping frame with implausible audio length (len=%d, offset=%d) [timecode=0x%04x video_len=%d video_offset=%d video_format=%x)\n",
                        card_index, int(audio_frame.len), int(audio_offset),
@@ -343,6 +358,9 @@ void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
        case 24:
                convert_fixed24_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
                break;
+       case 32:
+               convert_fixed32_to_fp32(&audio[0], 2, audio_frame.data + audio_offset, audio_format.num_channels, num_samples);
+               break;
        default:
                fprintf(stderr, "Cannot handle audio with %u bits per sample\n", audio_format.bits_per_sample);
                assert(false);