audio_format: remove the reverse_endian attribute

Eliminate support for reverse endian samples from the MPD core.  This
moves a lot of complexity to the plugins that really need it (only
ALSA and CDIO currently).

src/audio_format.c

@@ -22,12 +22,6 @@
 #include <assert.h>
 #include <stdio.h>
 
-#if G_BYTE_ORDER == G_BIG_ENDIAN
-#define REVERSE_ENDIAN_SUFFIX "_le"
-#else
-#define REVERSE_ENDIAN_SUFFIX "_be"
-#endif
-
 void
 audio_format_mask_apply(struct audio_format *af,
 			const struct audio_format *mask)
@@ -100,9 +94,8 @@ audio_format_to_string(const struct audio_format *af,
 	assert(af != NULL);
 	assert(s != NULL);
 
-	snprintf(s->buffer, sizeof(s->buffer), "%u:%s%s:%u",
+	snprintf(s->buffer, sizeof(s->buffer), "%u:%s:%u",
 		 af->sample_rate, sample_format_to_string(af->format),
-		 af->reverse_endian ? REVERSE_ENDIAN_SUFFIX : "",
 		 af->channels);
 
 	return s->buffer;

src/audio_format.h

@@ -88,13 +88,6 @@ struct audio_format {
 	 * fully supported currently.
 	 */
 	uint8_t channels;
-
-	/**
-	 * If zero, then samples are stored in host byte order.  If
-	 * nonzero, then samples are stored in the reverse host byte
-	 * order.
-	 */
-	bool reverse_endian;
 };
 
 /**
@@ -113,7 +106,6 @@ static inline void audio_format_clear(struct audio_format *af)
 	af->sample_rate = 0;
 	af->format = SAMPLE_FORMAT_UNDEFINED;
 	af->channels = 0;
-	af->reverse_endian = false;
 }
 
 /**
@@ -127,7 +119,6 @@ static inline void audio_format_init(struct audio_format *af,
 	af->sample_rate = sample_rate;
 	af->format = (uint8_t)format;
 	af->channels = channels;
-	af->reverse_endian = false;
 }
 
 /**
@@ -239,8 +230,7 @@ static inline bool audio_format_equals(const struct audio_format *a,
 {
 	return a->sample_rate == b->sample_rate &&
 		a->format == b->format &&
-		a->channels == b->channels &&
-		a->reverse_endian == b->reverse_endian;
+		a->channels == b->channels;
 }
 
 void

src/decoder_api.c

@@ -56,9 +56,6 @@ decoder_initialized(struct decoder *decoder,
 
 	dc->in_audio_format = *audio_format;
 	getOutputAudioFormat(audio_format, &dc->out_audio_format);
-	/* force host byte order, even if the decoder supplies reverse
-	   endian */
-	dc->out_audio_format.reverse_endian = false;
 
 	dc->seekable = seekable;
 	dc->total_time = total_time;

src/filter/convert_filter_plugin.c

@@ -141,7 +141,6 @@ convert_filter_set(struct filter *_filter,
 	assert(audio_format_valid(&filter->out_audio_format));
 	assert(out_audio_format != NULL);
 	assert(audio_format_valid(out_audio_format));
-	assert(!filter->in_audio_format.reverse_endian);
 
 	filter->out_audio_format = *out_audio_format;
 }

src/filter/normalize_filter_plugin.c

@@ -67,7 +67,6 @@ normalize_filter_open(struct filter *_filter,
 	struct normalize_filter *filter = (struct normalize_filter *)_filter;
 
 	audio_format->format = SAMPLE_FORMAT_S16;
-	audio_format->reverse_endian = false;
 
 	filter->compressor = Compressor_new(0);
 

src/filter/replay_gain_filter_plugin.c

@@ -140,8 +140,6 @@ replay_gain_filter_open(struct filter *_filter,
 	struct replay_gain_filter *filter =
 		(struct replay_gain_filter *)_filter;
 
-	audio_format->reverse_endian = false;
-
 	filter->audio_format = *audio_format;
 	pcm_buffer_init(&filter->buffer);
 

src/filter/volume_filter_plugin.c

@@ -74,8 +74,6 @@ volume_filter_open(struct filter *_filter, struct audio_format *audio_format,
 {
 	struct volume_filter *filter = (struct volume_filter *)_filter;
 
-	audio_format->reverse_endian = false;
-
 	filter->audio_format = *audio_format;
 	pcm_buffer_init(&filter->buffer);
 

src/output/alsa_output_plugin.c

@@ -314,10 +314,8 @@ alsa_output_try_reverse(snd_pcm_t *pcm, snd_pcm_hw_params_t *hwparams,
 		return -EINVAL;
 
 	int err = snd_pcm_hw_params_set_format(pcm, hwparams, alsa_format);
-	if (err == 0) {
+	if (err == 0)
 		audio_format->format = sample_format;
-		audio_format->reverse_endian = true;
-	}
 
 	return err;
 }

src/pcm_convert.c

@@ -21,7 +21,6 @@
 #include "pcm_convert.h"
 #include "pcm_channels.h"
 #include "pcm_format.h"
-#include "pcm_byteswap.h"
 #include "pcm_pack.h"
 #include "audio_format.h"
 #include "glib_compat.h"
@@ -45,7 +44,6 @@ void pcm_convert_init(struct pcm_convert_state *state)
 	pcm_buffer_init(&state->format_buffer);
 	pcm_buffer_init(&state->pack_buffer);
 	pcm_buffer_init(&state->channels_buffer);
-	pcm_buffer_init(&state->byteswap_buffer);
 }
 
 void pcm_convert_deinit(struct pcm_convert_state *state)
@@ -56,7 +54,6 @@ void pcm_convert_deinit(struct pcm_convert_state *state)
 	pcm_buffer_deinit(&state->format_buffer);
 	pcm_buffer_deinit(&state->pack_buffer);
 	pcm_buffer_deinit(&state->channels_buffer);
-	pcm_buffer_deinit(&state->byteswap_buffer);
 }
 
 void
@@ -164,11 +161,6 @@ pcm_convert_16(struct pcm_convert_state *state,
 			return NULL;
 	}
 
-	if (dest_format->reverse_endian) {
-		buf = pcm_byteswap_16(&state->byteswap_buffer, buf, len);
-		assert(buf != NULL);
-	}
-
 	*dest_size_r = len;
 	return buf;
 }
@@ -219,11 +211,6 @@ pcm_convert_24(struct pcm_convert_state *state,
 			return NULL;
 	}
 
-	if (dest_format->reverse_endian) {
-		buf = pcm_byteswap_32(&state->byteswap_buffer, buf, len);
-		assert(buf != NULL);
-	}
-
 	*dest_size_r = len;
 	return buf;
 }
@@ -261,8 +248,7 @@ pcm_convert_24_packed(struct pcm_convert_state *state,
 	size_t dest_size = num_samples * 3;
 
 	uint8_t *dest = pcm_buffer_get(&state->pack_buffer, dest_size);
-	pcm_pack_24(dest, buffer, buffer + num_samples,
-		    dest_format->reverse_endian);
+	pcm_pack_24(dest, buffer, buffer + num_samples);
 
 	*dest_size_r = dest_size;
 	return dest;
@@ -314,11 +300,6 @@ pcm_convert_32(struct pcm_convert_state *state,
 			return buf;
 	}
 
-	if (dest_format->reverse_endian) {
-		buf = pcm_byteswap_32(&state->byteswap_buffer, buf, len);
-		assert(buf != NULL);
-	}
-
 	*dest_size_r = len;
 	return buf;
 }
@@ -335,12 +316,6 @@ pcm_convert_float(struct pcm_convert_state *state,
 
 	assert(dest_format->format == SAMPLE_FORMAT_FLOAT);
 
-	if (src_format->reverse_endian || dest_format->reverse_endian) {
-		g_set_error_literal(error_r, pcm_convert_quark(), 0,
-				    "Reverse endian not supported");
-		return NULL;
-	}
-
 	/* convert channels first, hoping the source format is
 	   supported (float is not) */
 
@@ -392,20 +367,6 @@ pcm_convert(struct pcm_convert_state *state,
 	    size_t *dest_size_r,
 	    GError **error_r)
 {
-	if (src_format->reverse_endian) {
-		/* convert to host byte order, because all of our
-		   conversion libraries assume host byte order */
-
-		src = pcm_byteswap(&state->byteswap_buffer, src_format->format,
-				   src, src_size);
-		if (src == NULL) {
-			g_set_error(error_r, pcm_convert_quark(), 0,
-				    "PCM byte order change of format '%s' is not implemented",
-				    sample_format_to_string(src_format->format));
-			return NULL;
-		}
-	}
-
 	struct audio_format float_format;
 	if (src_format->format == SAMPLE_FORMAT_DSD) {
 		size_t f_size;

src/pcm_convert.h

@@ -47,9 +47,6 @@ struct pcm_convert_state {
 
 	/** the buffer for converting the channel count */
 	struct pcm_buffer channels_buffer;
-
-	/** the buffer for swapping the byte order */
-	struct pcm_buffer byteswap_buffer;
 };
 
 static inline GQuark

src/pcm_format.c

@@ -76,7 +76,7 @@ pcm_allocate_24_to_24p32(struct pcm_buffer *buffer, const uint8_t *src,
 	int32_t *dest;
 	*dest_size_r = src_size / 3 * sizeof(*dest);
 	dest = pcm_buffer_get(buffer, *dest_size_r);
-	pcm_unpack_24(dest, src, pcm_end_pointer(src, src_size), false);
+	pcm_unpack_24(dest, src, pcm_end_pointer(src, src_size));
 	return dest;
 }
 

src/pcm_pack.c

@@ -22,11 +22,11 @@
 #include <glib.h>
 
 static void
-pack_sample(uint8_t *dest, const int32_t *src0, bool reverse_endian)
+pack_sample(uint8_t *dest, const int32_t *src0)
 {
 	const uint8_t *src = (const uint8_t *)src0;
 
-	if ((G_BYTE_ORDER == G_BIG_ENDIAN) != reverse_endian)
+	if (G_BYTE_ORDER == G_BIG_ENDIAN)
 		++src;
 
 	*dest++ = *src++;
@@ -35,31 +35,23 @@ pack_sample(uint8_t *dest, const int32_t *src0, bool reverse_endian)
 }
 
 void
-pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end,
-	    bool reverse_endian)
+pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end)
 {
 	/* duplicate loop to help the compiler's optimizer (constant
 	   parameter to the pack_sample() inline function) */
 
-	if (G_LIKELY(!reverse_endian)) {
-		while (src < src_end) {
-			pack_sample(dest, src++, false);
-			dest += 3;
-		}
-	} else {
-		while (src < src_end) {
-			pack_sample(dest, src++, true);
-			dest += 3;
-		}
+	while (src < src_end) {
+		pack_sample(dest, src++);
+		dest += 3;
 	}
 }
 
 static void
-unpack_sample(int32_t *dest0, const uint8_t *src, bool reverse_endian)
+unpack_sample(int32_t *dest0, const uint8_t *src)
 {
 	uint8_t *dest = (uint8_t *)dest0;
 
-	if ((G_BYTE_ORDER == G_BIG_ENDIAN) != reverse_endian)
+	if (G_BYTE_ORDER == G_BIG_ENDIAN)
 		/* extend the sign bit to the most fourth byte */
 		*dest++ = *src & 0x80 ? 0xff : 0x00;
 
@@ -67,27 +59,19 @@ unpack_sample(int32_t *dest0, const uint8_t *src, bool reverse_endian)
 	*dest++ = *src++;
 	*dest++ = *src;
 
-	if ((G_BYTE_ORDER == G_LITTLE_ENDIAN) != reverse_endian)
+	if (G_BYTE_ORDER != G_LITTLE_ENDIAN)
 		/* extend the sign bit to the most fourth byte */
 		*dest++ = *src & 0x80 ? 0xff : 0x00;
 }
 
 void
-pcm_unpack_24(int32_t *dest, const uint8_t *src, const uint8_t *src_end,
-	      bool reverse_endian)
+pcm_unpack_24(int32_t *dest, const uint8_t *src, const uint8_t *src_end)
 {
 	/* duplicate loop to help the compiler's optimizer (constant
 	   parameter to the unpack_sample() inline function) */
 
-	if (G_LIKELY(!reverse_endian)) {
-		while (src < src_end) {
-			unpack_sample(dest++, src, false);
-			src += 3;
-		}
-	} else {
-		while (src < src_end) {
-			unpack_sample(dest++, src, true);
-			src += 3;
-		}
+	while (src < src_end) {
+		unpack_sample(dest++, src);
+		src += 3;
 	}
 }

src/pcm_pack.h

@@ -37,11 +37,9 @@
  * @param dest the destination buffer (array of triples)
  * @param src the source buffer
  * @param num_samples the number of samples to convert
- * @param reverse_endian is src and dest in non-host byte order?
  */
 void
-pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end,
-	    bool reverse_endian);
+pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end);
 
 /**
  * Converts packed 24 bit samples (3 bytes per sample) to padded 24
@@ -50,10 +48,8 @@ pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end,
  * @param dest the destination buffer
  * @param src the source buffer (array of triples)
  * @param num_samples the number of samples to convert
- * @param reverse_endian is src and dest in non-host byte order?
  */
 void
-pcm_unpack_24(int32_t *dest, const uint8_t *src, const uint8_t *src_end,
-	      bool reverse_endian);
+pcm_unpack_24(int32_t *dest, const uint8_t *src, const uint8_t *src_end);
 
 #endif

test/test_pcm_pack.c

@@ -45,7 +45,7 @@ test_pcm_pack_24(void)
 
 	uint8_t dest[N * 3];
 
-	pcm_pack_24(dest, src, src + N, false);
+	pcm_pack_24(dest, src, src + N);
 
 	for (unsigned i = 0; i < N; ++i) {
 		int32_t d;
@@ -72,7 +72,7 @@ test_pcm_unpack_24(void)
 
 	int32_t dest[N];
 
-	pcm_unpack_24(dest, src, src + G_N_ELEMENTS(src), false);
+	pcm_unpack_24(dest, src, src + G_N_ELEMENTS(src));
 
 	for (unsigned i = 0; i < N; ++i) {
 		int32_t s;