add force_mid_side_stereo option

diff --git a/src/libFLAC/encoder.c b/src/libFLAC/encoder.c
index 9f0d4df..d1206db 100644 (file)
--- a/src/libFLAC/encoder.c
+++ b/src/libFLAC/encoder.c
@@ -64,7 +64,7 @@ typedef struct FLAC__EncoderPrivate {
 
 static bool encoder_resize_buffers_(FLAC__Encoder *encoder, unsigned new_size);
 static bool encoder_process_frame_(FLAC__Encoder *encoder, bool is_last_frame);
-static bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame, const FLAC__FrameHeader *frame_header, unsigned channels, const int32 *integer_signal[], const real *real_signal[], FLAC__BitBuffer *bitbuffer);
+static bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame, bool verbatim_only, const FLAC__FrameHeader *frame_header, unsigned channels, const int32 *integer_signal[], const real *real_signal[], FLAC__BitBuffer *bitbuffer);
 static unsigned encoder_evaluate_constant_subframe_(const int32 signal, unsigned bits_per_sample, FLAC__Subframe *subframe);
 static unsigned encoder_evaluate_fixed_subframe_(const int32 signal[], int32 residual[], uint32 abs_residual[], unsigned blocksize, unsigned bits_per_sample, unsigned order, unsigned rice_parameter, unsigned max_partition_order, FLAC__Subframe *subframe);
 static unsigned encoder_evaluate_lpc_subframe_(const int32 signal[], int32 residual[], uint32 abs_residual[], const real lp_coeff[], unsigned blocksize, unsigned bits_per_sample, unsigned order, unsigned qlp_coeff_precision, unsigned rice_parameter, unsigned max_partition_order, FLAC__Subframe *subframe);
@@ -88,6 +88,7 @@ const char *FLAC__EncoderStateString[] = {
        "FLAC__ENCODER_INVALID_QLP_COEFF_PRECISION",
        "FLAC__ENCODER_MID_SIDE_CHANNELS_MISMATCH",
        "FLAC__ENCODER_MID_SIDE_SAMPLE_SIZE_MISMATCH",
+       "FLAC__ENCODER_ILLEGAL_MID_SIDE_FORCE",
        "FLAC__ENCODER_BLOCK_SIZE_TOO_SMALL_FOR_LPC_ORDER",
        "FLAC__ENCODER_NOT_STREAMABLE",
        "FLAC__ENCODER_FRAMING_ERROR",
@@ -239,6 +240,9 @@ FLAC__EncoderState FLAC__encoder_init(FLAC__Encoder *encoder, FLAC__EncoderWrite
        if(encoder->do_mid_side_stereo && encoder->bits_per_sample > 16)
                return encoder->state = FLAC__ENCODER_MID_SIDE_SAMPLE_SIZE_MISMATCH;
 
+       if(encoder->force_mid_side_stereo && !encoder->do_mid_side_stereo)
+               return encoder->state = FLAC__ENCODER_ILLEGAL_MID_SIDE_FORCE;
+
        if(encoder->bits_per_sample == 0 || encoder->bits_per_sample > FLAC__MAX_BITS_PER_SAMPLE)
                return encoder->state = FLAC__ENCODER_INVALID_BITS_PER_SAMPLE;
 
@@ -535,7 +539,7 @@ bool encoder_process_frame_(FLAC__Encoder *encoder, bool is_last_frame)
                return false;
        }
 
-       if(!encoder_process_subframes_(encoder, is_last_frame, &frame_header, encoder->channels, encoder->guts->integer_signal, encoder->guts->real_signal, &encoder->guts->frame))
+       if(!encoder_process_subframes_(encoder, is_last_frame, encoder->force_mid_side_stereo, &frame_header, encoder->channels, encoder->guts->integer_signal, encoder->guts->real_signal, &encoder->guts->frame))
                return false;
 
        smallest_frame = &encoder->guts->frame;
@@ -563,48 +567,50 @@ bool encoder_process_frame_(FLAC__Encoder *encoder, bool is_last_frame)
                integer_signal[1] = encoder->guts->integer_signal_mid_side[1]; /* side channel */
                real_signal[0] = encoder->guts->real_signal_mid_side[0]; /* mid channel */
                real_signal[1] = encoder->guts->real_signal_mid_side[1]; /* side channel */
-               if(!encoder_process_subframes_(encoder, is_last_frame, &frame_header, encoder->channels, integer_signal, real_signal, &encoder->guts->frame_mid_side))
+               if(!encoder_process_subframes_(encoder, is_last_frame, false, &frame_header, encoder->channels, integer_signal, real_signal, &encoder->guts->frame_mid_side))
                        return false;
                if(encoder->guts->frame_mid_side.total_bits < smallest_frame->total_bits)
                        smallest_frame = &encoder->guts->frame_mid_side;
 
-               /* left-side */
-               frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE;
-               if(!FLAC__bitbuffer_clear(&encoder->guts->frame_left_side)) {
-                       encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
-                       return false;
-               }
-               if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame_left_side)) {
-                       encoder->state = FLAC__ENCODER_FRAMING_ERROR;
-                       return false;
-               }
-               integer_signal[0] = encoder->guts->integer_signal[0]; /* left channel */
-               integer_signal[1] = encoder->guts->integer_signal_mid_side[1]; /* side channel */
-               real_signal[0] = encoder->guts->real_signal[0]; /* left channel */
-               real_signal[1] = encoder->guts->real_signal_mid_side[1]; /* side channel */
-               if(!encoder_process_subframes_(encoder, is_last_frame, &frame_header, encoder->channels, integer_signal, real_signal, &encoder->guts->frame_left_side))
-                       return false;
-               if(encoder->guts->frame_left_side.total_bits < smallest_frame->total_bits)
-                       smallest_frame = &encoder->guts->frame_left_side;
+               if(!encoder->force_mid_side_stereo) {
+                       /* left-side */
+                       frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE;
+                       if(!FLAC__bitbuffer_clear(&encoder->guts->frame_left_side)) {
+                               encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
+                               return false;
+                       }
+                       if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame_left_side)) {
+                               encoder->state = FLAC__ENCODER_FRAMING_ERROR;
+                               return false;
+                       }
+                       integer_signal[0] = encoder->guts->integer_signal[0]; /* left channel */
+                       integer_signal[1] = encoder->guts->integer_signal_mid_side[1]; /* side channel */
+                       real_signal[0] = encoder->guts->real_signal[0]; /* left channel */
+                       real_signal[1] = encoder->guts->real_signal_mid_side[1]; /* side channel */
+                       if(!encoder_process_subframes_(encoder, is_last_frame, false, &frame_header, encoder->channels, integer_signal, real_signal, &encoder->guts->frame_left_side))
+                               return false;
+                       if(encoder->guts->frame_left_side.total_bits < smallest_frame->total_bits)
+                               smallest_frame = &encoder->guts->frame_left_side;
 
-               /* right-side */
-               frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE;
-               if(!FLAC__bitbuffer_clear(&encoder->guts->frame_right_side)) {
-                       encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
-                       return false;
-               }
-               if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame_right_side)) {
-                       encoder->state = FLAC__ENCODER_FRAMING_ERROR;
-                       return false;
+                       /* right-side */
+                       frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE;
+                       if(!FLAC__bitbuffer_clear(&encoder->guts->frame_right_side)) {
+                               encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
+                               return false;
+                       }
+                       if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame_right_side)) {
+                               encoder->state = FLAC__ENCODER_FRAMING_ERROR;
+                               return false;
+                       }
+                       integer_signal[0] = encoder->guts->integer_signal_mid_side[1]; /* side channel */
+                       integer_signal[1] = encoder->guts->integer_signal[1]; /* right channel */
+                       real_signal[0] = encoder->guts->real_signal_mid_side[1]; /* side channel */
+                       real_signal[1] = encoder->guts->real_signal[1]; /* right channel */
+                       if(!encoder_process_subframes_(encoder, is_last_frame, false, &frame_header, encoder->channels, integer_signal, real_signal, &encoder->guts->frame_right_side))
+                               return false;
+                       if(encoder->guts->frame_right_side.total_bits < smallest_frame->total_bits)
+                               smallest_frame = &encoder->guts->frame_right_side;
                }
-               integer_signal[0] = encoder->guts->integer_signal_mid_side[1]; /* side channel */
-               integer_signal[1] = encoder->guts->integer_signal[1]; /* right channel */
-               real_signal[0] = encoder->guts->real_signal_mid_side[1]; /* side channel */
-               real_signal[1] = encoder->guts->real_signal[1]; /* right channel */
-               if(!encoder_process_subframes_(encoder, is_last_frame, &frame_header, encoder->channels, integer_signal, real_signal, &encoder->guts->frame_right_side))
-                       return false;
-               if(encoder->guts->frame_right_side.total_bits < smallest_frame->total_bits)
-                       smallest_frame = &encoder->guts->frame_right_side;
        }
 
        /*
@@ -638,7 +644,7 @@ bool encoder_process_frame_(FLAC__Encoder *encoder, bool is_last_frame)
        return true;
 }
 
-bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame, const FLAC__FrameHeader *frame_header, unsigned channels, const int32 *integer_signal[], const real *real_signal[], FLAC__BitBuffer *frame)
+bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame, bool verbatim_only, const FLAC__FrameHeader *frame_header, unsigned channels, const int32 *integer_signal[], const real *real_signal[], FLAC__BitBuffer *frame)
 {
        real fixed_residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1];
        real lpc_residual_bits_per_sample;
@@ -669,7 +675,7 @@ bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame, cons
                /* verbatim subframe is the baseline against which we measure other compressed subframes */
                best_bits = encoder_evaluate_verbatim_subframe_(frame_header->blocksize, frame_header->bits_per_sample, &(encoder->guts->best_subframe));
 
-               if(frame_header->blocksize >= FLAC__MAX_FIXED_ORDER) {
+               if(!verbatim_only && frame_header->blocksize >= FLAC__MAX_FIXED_ORDER) {
                        /* check for constant subframe */
                        guess_fixed_order = FLAC__fixed_compute_best_predictor(integer_signal[channel]+FLAC__MAX_FIXED_ORDER, frame_header->blocksize-FLAC__MAX_FIXED_ORDER, fixed_residual_bits_per_sample);
                        if(fixed_residual_bits_per_sample[1] == 0.0) {