Fix redundantly setting i2s_format

[robert-alfaro]

The i2s format configuration was being set upon every call to play audio regardless of an actual format change because the variable being used to track and compare against was always new.

By moving the tracking variable to the audio instance context, we can safely compare and set when necessary.

[Copilot]

Pull Request Overview

This PR prevents unnecessary reconfiguration of the I2S format on each audio playback by storing the last-used format in the audio_instance_t context instead of a temporary variable.

• Added i2s_format field to audio_instance_t
• Removed local i2s_format and replaced its uses with the context field
• Zero-initialized instance.i2s_format in audio_player_new

Comments suppressed due to low confidence (1)

audio_player.cpp:365

• The format specifiers %lu may not match the type of bits_per_sample and channels. Verify their types and use %d or %zu accordingly to avoid logging mismatches.

LOGI_1("format change: sr=%d, bit=%lu, ch=%lu",

[Copilot]

[nitpick] For consistency and future support of multiple instances, consider using i->i2s_format instead of the global instance inside this function.

Suggested change

	if ((instance.i2s_format.sample_rate != i->output.fmt.sample_rate) ||
	(instance.i2s_format.channels != i->output.fmt.channels) ||
	(instance.i2s_format.bits_per_sample != i->output.fmt.bits_per_sample)) {
	instance.i2s_format = i->output.fmt;
	LOGI_1("format change: sr=%d, bit=%lu, ch=%lu",
	instance.i2s_format.sample_rate,
	instance.i2s_format.bits_per_sample,
	instance.i2s_format.channels);
	i2s_slot_mode_t channel_setting = (instance.i2s_format.channels == 1) ? I2S_SLOT_MODE_MONO : I2S_SLOT_MODE_STEREO;
	ret = i->config.clk_set_fn(instance.i2s_format.sample_rate,
	instance.i2s_format.bits_per_sample,
	if ((i->i2s_format.sample_rate != i->output.fmt.sample_rate) ||
	(i->i2s_format.channels != i->output.fmt.channels) ||
	(i->i2s_format.bits_per_sample != i->output.fmt.bits_per_sample)) {
	i->i2s_format = i->output.fmt;
	LOGI_1("format change: sr=%d, bit=%lu, ch=%lu",
	i->i2s_format.sample_rate,
	i->i2s_format.bits_per_sample,
	i->i2s_format.channels);
	i2s_slot_mode_t channel_setting = (i->i2s_format.channels == 1) ? I2S_SLOT_MODE_MONO : I2S_SLOT_MODE_STEREO;
	ret = i->config.clk_set_fn(i->i2s_format.sample_rate,
	i->i2s_format.bits_per_sample,

[Copilot]

This still references the removed local i2s_format. Update it to instance.i2s_format.bits_per_sample (or i->i2s_format.bits_per_sample if following suggestion above) so the correct field is used.

[chmorgan]

Thank you for your contribution!