static void
gst_mpg123_audio_dec_flush (GstAudioDecoder * dec, gboolean hard)
{
int error;
GstMpg123AudioDec *mpg123_decoder;
hard = hard;
GST_LOG_OBJECT (dec, "Flushing decoder");
mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
g_assert (mpg123_decoder->handle != NULL);
/* Flush by reopening the feed */
mpg123_close (mpg123_decoder->handle);
error = mpg123_open_feed (mpg123_decoder->handle);
if (G_UNLIKELY (error != MPG123_OK)) {
GST_ELEMENT_ERROR (dec, LIBRARY, INIT, (NULL),
("Error while reopening mpg123 feed: %s",
mpg123_plain_strerror (error)));
mpg123_close (mpg123_decoder->handle);
mpg123_delete (mpg123_decoder->handle);
mpg123_decoder->handle = NULL;
}
mpg123_decoder->has_next_audioinfo = FALSE;
/* opening/closing feeds do not affect the format defined by the
* mpg123_format() call that was made in gst_mpg123_audio_dec_set_format(),
* and since the up/downstream caps are not expected to change here, no
* mpg123_format() calls are done */
}
static void
gst_mpg123_audio_dec_finalize (GObject * object)
{
GstMpg123AudioDec *mpg123_decoder = GST_MPG123_AUDIO_DEC (object);
if (G_LIKELY (mpg123_decoder->handle != NULL)) {
mpg123_delete (mpg123_decoder->handle);
mpg123_decoder->handle = NULL;
}
}
static void
gst_mpg123_audio_dec_finalize (GObject * object)
{
GstMpg123AudioDec *mpg123_decoder = GST_MPG123_AUDIO_DEC (object);
if (G_LIKELY (mpg123_decoder->handle != NULL)) {
mpg123_delete (mpg123_decoder->handle);
mpg123_decoder->handle = NULL;
}
G_OBJECT_CLASS (gst_mpg123_audio_dec_parent_class)->finalize (object);
}
static gboolean
gst_mpg123_audio_dec_start (GstAudioDecoder * dec)
{
GstMpg123AudioDec *mpg123_decoder;
int error;
mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
error = 0;
mpg123_decoder->handle = mpg123_new (NULL, &error);
mpg123_decoder->has_next_audioinfo = FALSE;
mpg123_decoder->frame_offset = 0;
/* Initially, the mpg123 handle comes with a set of default formats
* supported. This clears this set. This is necessary, since only one
* format shall be supported (see set_format for more). */
mpg123_format_none (mpg123_decoder->handle);
/* Built-in mpg123 support for gapless decoding is disabled for now,
* since it does not work well with seeking */
mpg123_param (mpg123_decoder->handle, MPG123_REMOVE_FLAGS, MPG123_GAPLESS, 0);
/* Tells mpg123 to use a small read-ahead buffer for better MPEG sync;
* essential for MP3 radio streams */
mpg123_param (mpg123_decoder->handle, MPG123_ADD_FLAGS, MPG123_SEEKBUFFER, 0);
/* Sets the resync limit to the end of the stream (otherwise mpg123 may give
* up on decoding prematurely, especially with mp3 web radios) */
mpg123_param (mpg123_decoder->handle, MPG123_RESYNC_LIMIT, -1, 0);
#if MPG123_API_VERSION >= 36
/* The precise API version where MPG123_AUTO_RESAMPLE appeared is
* somewhere between 29 and 36 */
/* Don't let mpg123 resample output */
mpg123_param (mpg123_decoder->handle, MPG123_REMOVE_FLAGS,
MPG123_AUTO_RESAMPLE, 0);
#endif
/* Don't let mpg123 print messages to stdout/stderr */
mpg123_param (mpg123_decoder->handle, MPG123_ADD_FLAGS, MPG123_QUIET, 0);
/* Open in feed mode (= encoded data is fed manually into the handle). */
error = mpg123_open_feed (mpg123_decoder->handle);
if (G_UNLIKELY (error != MPG123_OK)) {
GST_ELEMENT_ERROR (dec, LIBRARY, INIT, (NULL),
("%s", mpg123_strerror (mpg123_decoder->handle)));
mpg123_close (mpg123_decoder->handle);
mpg123_delete (mpg123_decoder->handle);
mpg123_decoder->handle = NULL;
return FALSE;
}
GST_INFO_OBJECT (dec, "mpg123 decoder started");
return TRUE;
}
static gboolean
gst_mpg123_audio_dec_stop (GstAudioDecoder * dec)
{
GstMpg123AudioDec *mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
if (G_LIKELY (mpg123_decoder->handle != NULL)) {
mpg123_close (mpg123_decoder->handle);
mpg123_delete (mpg123_decoder->handle);
mpg123_decoder->handle = NULL;
}
GST_INFO_OBJECT (dec, "mpg123 decoder stopped");
return TRUE;
}
static gboolean
gst_mpg123_audio_dec_start (GstAudioDecoder * dec)
{
GstMpg123AudioDec *mpg123_decoder;
int error;
mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
error = 0;
mpg123_decoder->handle = mpg123_new (NULL, &error);
mpg123_decoder->has_next_audioinfo = FALSE;
mpg123_decoder->frame_offset = 0;
/*
Initially, the mpg123 handle comes with a set of default formats supported. This clears this set.
This is necessary, since only one format shall be supported (see set_format for more).
*/
mpg123_format_none (mpg123_decoder->handle);
mpg123_param (mpg123_decoder->handle, MPG123_REMOVE_FLAGS, MPG123_GAPLESS, 0); /* Built-in mpg123 support for gapless decoding is disabled for now, since it does not work well with seeking */
mpg123_param (mpg123_decoder->handle, MPG123_ADD_FLAGS, MPG123_SEEKBUFFER, 0); /* Tells mpg123 to use a small read-ahead buffer for better MPEG sync; essential for MP3 radio streams */
mpg123_param (mpg123_decoder->handle, MPG123_RESYNC_LIMIT, -1, 0); /* Sets the resync limit to the end of the stream (e.g. don't give up prematurely) */
/* Open in feed mode (= encoded data is fed manually into the handle). */
error = mpg123_open_feed (mpg123_decoder->handle);
if (G_UNLIKELY (error != MPG123_OK)) {
GstElement *element = GST_ELEMENT (dec);
GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
("Error opening mpg123 feed: %s", mpg123_plain_strerror (error)));
mpg123_close (mpg123_decoder->handle);
mpg123_delete (mpg123_decoder->handle);
mpg123_decoder->handle = NULL;
return FALSE;
}
GST_DEBUG_OBJECT (dec, "mpg123 decoder started");
return TRUE;
}
static void
gst_mpg123_audio_dec_flush (GstAudioDecoder * dec, gboolean hard)
{
int error;
GstMpg123AudioDec *mpg123_decoder;
hard = hard;
GST_DEBUG_OBJECT (dec, "Flushing decoder");
mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
if (G_UNLIKELY (mpg123_decoder->handle == NULL)) {
GstElement *element = GST_ELEMENT (dec);
GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
("mpg123 handle is NULL"));
return;
}
/* Flush by reopening the feed */
mpg123_close (mpg123_decoder->handle);
error = mpg123_open_feed (mpg123_decoder->handle);
if (G_UNLIKELY (error != MPG123_OK)) {
GstElement *element = GST_ELEMENT (dec);
GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
("Error reopening mpg123 feed: %s", mpg123_plain_strerror (error)));
mpg123_close (mpg123_decoder->handle);
mpg123_delete (mpg123_decoder->handle);
mpg123_decoder->handle = NULL;
}
mpg123_decoder->has_next_audioinfo = FALSE;
/*
opening/closing feeds do not affect the format defined by the mpg123_format() call that was made in gst_mpg123_audio_dec_set_format(),
and since the up/downstream caps are not expected to change here, no mpg123_format() calls are done
*/
}
static gboolean
gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec, GstCaps * input_caps)
{
/* Using the parsed information upstream, and the list of allowed caps
* downstream, this code tries to find a suitable audio info. It is important
* to keep in mind that the rate and number of channels should never deviate
* from the one the bitstream has, otherwise mpg123 has to mix channels and/or
* resample (and as its docs say, its internal resampler is very crude). The
* sample format, however, can be chosen freely, because the MPEG specs do not
* mandate any special format. Therefore, rate and number of channels are taken
* from upstream (which parsed the MPEG frames, so the input_caps contain
* exactly the rate and number of channels the bitstream actually has), while
* the sample format is chosen by trying out all caps that are allowed by
* downstream. This way, the output is adjusted to what the downstream prefers.
*
* Also, the new output audio info is not set immediately. Instead, it is
* considered the "next audioinfo". The code waits for mpg123 to notice the new
* format (= when mpg123_decode_frame() returns MPG123_AUDIO_DEC_NEW_FORMAT),
* and then sets the next audioinfo. Otherwise, the next audioinfo is set too
* soon, which may cause problems with mp3s containing several format headers.
* One example would be an mp3 with the first 30 seconds using 44.1 kHz, then
* the next 30 seconds using 32 kHz. Rare, but possible.
*
* STEPS:
*
* 1. get rate and channels from input_caps
* 2. get allowed caps from src pad
* 3. for each structure in allowed caps:
* 3.1. take format
* 3.2. if the combination of format with rate and channels is unsupported by
* mpg123, go to (3), or exit with error if there are no more structures
* to try
* 3.3. create next audioinfo out of rate,channels,format, and exit
*/
int rate, channels;
GstMpg123AudioDec *mpg123_decoder;
GstCaps *allowed_srccaps;
guint structure_nr;
gboolean match_found = FALSE;
mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
g_assert (mpg123_decoder->handle != NULL);
mpg123_decoder->has_next_audioinfo = FALSE;
/* Get rate and channels from input_caps */
{
GstStructure *structure;
gboolean err = FALSE;
/* Only the first structure is used (multiple
* input caps structures don't make sense */
structure = gst_caps_get_structure (input_caps, 0);
if (!gst_structure_get_int (structure, "rate", &rate)) {
err = TRUE;
GST_ERROR_OBJECT (dec, "Input caps do not have a rate value");
}
if (!gst_structure_get_int (structure, "channels", &channels)) {
err = TRUE;
GST_ERROR_OBJECT (dec, "Input caps do not have a channel value");
}
if (err)
return FALSE;
}
/* Get the caps that are allowed by downstream */
{
GstCaps *allowed_srccaps_unnorm =
gst_pad_get_allowed_caps (GST_AUDIO_DECODER_SRC_PAD (dec));
allowed_srccaps = gst_caps_normalize (allowed_srccaps_unnorm);
}
/* Go through all allowed caps, pick the first one that matches */
for (structure_nr = 0; structure_nr < gst_caps_get_size (allowed_srccaps);
++structure_nr) {
GstStructure *structure;
gchar const *format_str;
GstAudioFormat format;
int encoding;
structure = gst_caps_get_structure (allowed_srccaps, structure_nr);
format_str = gst_structure_get_string (structure, "format");
if (format_str == NULL) {
GST_DEBUG_OBJECT (dec, "Could not get format from src caps");
continue;
}
format = gst_audio_format_from_string (format_str);
if (format == GST_AUDIO_FORMAT_UNKNOWN) {
GST_DEBUG_OBJECT (dec, "Unknown format %s", format_str);
continue;
}
switch (format) {
case GST_AUDIO_FORMAT_S16:
encoding = MPG123_ENC_SIGNED_16;
break;
case GST_AUDIO_FORMAT_S24:
encoding = MPG123_ENC_SIGNED_24;
break;
case GST_AUDIO_FORMAT_S32:
encoding = MPG123_ENC_SIGNED_32;
break;
case GST_AUDIO_FORMAT_U16:
encoding = MPG123_ENC_UNSIGNED_16;
break;
case GST_AUDIO_FORMAT_U24:
encoding = MPG123_ENC_UNSIGNED_24;
break;
case GST_AUDIO_FORMAT_U32:
encoding = MPG123_ENC_UNSIGNED_32;
break;
case GST_AUDIO_FORMAT_F32:
encoding = MPG123_ENC_FLOAT_32;
break;
default:
GST_DEBUG_OBJECT (dec,
"Format %s in srccaps is not supported", format_str);
continue;
}
{
int err;
/* Cleanup old formats & set new one */
mpg123_format_none (mpg123_decoder->handle);
err = mpg123_format (mpg123_decoder->handle, rate, channels, encoding);
if (err != MPG123_OK) {
GST_DEBUG_OBJECT (dec,
"mpg123 cannot use caps %" GST_PTR_FORMAT
" because mpg123_format() failed: %s", structure,
mpg123_strerror (mpg123_decoder->handle));
continue;
}
}
gst_audio_info_init (&(mpg123_decoder->next_audioinfo));
gst_audio_info_set_format (&(mpg123_decoder->next_audioinfo), format, rate,
channels, NULL);
GST_LOG_OBJECT (dec, "The next audio format is: %s, %u Hz, %u channels",
format_str, rate, channels);
mpg123_decoder->has_next_audioinfo = TRUE;
match_found = TRUE;
break;
}
gst_caps_unref (allowed_srccaps);
return match_found;
}
static GstFlowReturn
gst_mpg123_audio_dec_handle_frame (GstAudioDecoder * dec,
GstBuffer * input_buffer)
{
GstMpg123AudioDec *mpg123_decoder;
int decode_error;
unsigned char *decoded_bytes;
size_t num_decoded_bytes;
GstFlowReturn retval;
mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
g_assert (mpg123_decoder->handle != NULL);
/* The actual decoding */
{
/* feed input data (if there is any) */
if (G_LIKELY (input_buffer != NULL)) {
GstMapInfo info;
if (gst_buffer_map (input_buffer, &info, GST_MAP_READ)) {
mpg123_feed (mpg123_decoder->handle, info.data, info.size);
gst_buffer_unmap (input_buffer, &info);
} else {
GST_ERROR_OBJECT (mpg123_decoder, "gst_memory_map() failed");
return GST_FLOW_ERROR;
}
}
/* Try to decode a frame */
decoded_bytes = NULL;
num_decoded_bytes = 0;
decode_error = mpg123_decode_frame (mpg123_decoder->handle,
&mpg123_decoder->frame_offset, &decoded_bytes, &num_decoded_bytes);
}
retval = GST_FLOW_OK;
switch (decode_error) {
case MPG123_NEW_FORMAT:
/* As mentioned in gst_mpg123_audio_dec_set_format(), the next audioinfo
* is not set immediately; instead, the code waits for mpg123 to take
* note of the new format, and then sets the audioinfo. This fixes glitches
* with mp3s containing several format headers (for example, first half
* using 44.1kHz, second half 32 kHz) */
GST_LOG_OBJECT (dec,
"mpg123 reported a new format -> setting next srccaps");
gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder, decoded_bytes,
num_decoded_bytes);
/* If there is a next audioinfo, use it, then set has_next_audioinfo to
* FALSE, to make sure gst_audio_decoder_set_output_format() isn't called
* again until set_format is called by the base class */
if (mpg123_decoder->has_next_audioinfo) {
if (!gst_audio_decoder_set_output_format (dec,
&(mpg123_decoder->next_audioinfo))) {
GST_WARNING_OBJECT (dec, "Unable to set output format");
retval = GST_FLOW_NOT_NEGOTIATED;
}
mpg123_decoder->has_next_audioinfo = FALSE;
}
break;
case MPG123_NEED_MORE:
case MPG123_OK:
retval = gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder,
decoded_bytes, num_decoded_bytes);
break;
case MPG123_DONE:
/* If this happens, then the upstream parser somehow missed the ending
* of the bitstream */
GST_LOG_OBJECT (dec, "mpg123 is done decoding");
gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder, decoded_bytes,
num_decoded_bytes);
retval = GST_FLOW_EOS;
break;
default:
{
/* Anything else is considered an error */
int errcode;
switch (decode_error) {
case MPG123_ERR:
errcode = mpg123_errcode (mpg123_decoder->handle);
break;
default:
errcode = decode_error;
}
switch (errcode) {
case MPG123_BAD_OUTFORMAT:{
GstCaps *input_caps =
gst_pad_get_current_caps (GST_AUDIO_DECODER_SINK_PAD (dec));
GST_ELEMENT_ERROR (dec, STREAM, FORMAT, (NULL),
("Output sample format could not be used when trying to decode frame. "
"This is typically caused when the input caps (often the sample "
"rate) do not match the actual format of the audio data. "
"Input caps: %" GST_PTR_FORMAT, input_caps)
);
gst_caps_unref (input_caps);
break;
}
default:{
char const *errmsg = mpg123_plain_strerror (errcode);
GST_ERROR_OBJECT (dec, "Reported error: %s", errmsg);
}
}
retval = GST_FLOW_ERROR;
}
}
return retval;
}
static GstFlowReturn
gst_mpg123_audio_dec_handle_frame (GstAudioDecoder * dec, GstBuffer * buffer)
{
GstMpg123AudioDec *mpg123_decoder;
int decode_error;
unsigned char *decoded_bytes;
size_t num_decoded_bytes;
if (G_UNLIKELY (!buffer))
return GST_FLOW_OK;
mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
if (G_UNLIKELY (mpg123_decoder->handle == NULL)) {
GstElement *element = GST_ELEMENT (dec);
GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
("mpg123 handle is NULL"));
return GST_FLOW_ERROR;
}
/* The actual decoding */
{
unsigned char const *inmemory;
size_t inmemsize;
GstMemory *memory;
GstMapInfo info;
memory = gst_buffer_get_all_memory (buffer);
if (memory == NULL)
return GST_FLOW_ERROR;
if (!gst_memory_map (memory, &info, GST_MAP_READ)) {
gst_memory_unref (memory);
return GST_FLOW_ERROR;
}
inmemory = info.data;
inmemsize = info.size;
mpg123_feed (mpg123_decoder->handle, inmemory, inmemsize);
decoded_bytes = NULL;
num_decoded_bytes = 0;
decode_error = mpg123_decode_frame (mpg123_decoder->handle,
&mpg123_decoder->frame_offset, &decoded_bytes, &num_decoded_bytes);
gst_memory_unmap (memory, &info);
gst_memory_unref (memory);
}
switch (decode_error) {
case MPG123_NEW_FORMAT:
/*
As mentioned in gst_mpg123_audio_dec_set_format(), the next audioinfo is not set immediately;
instead, the code waits for mpg123 to take note of the new format, and then sets the audioinfo
This fixes glitches with mp3s containing several format headers (for example, first half using 44.1kHz, second half 32 kHz)
*/
GST_DEBUG_OBJECT (dec,
"mpg123 reported a new format -> setting next srccaps");
gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder, decoded_bytes,
num_decoded_bytes);
/*
If there is a next audioinfo, use it, then set has_next_audioinfo to FALSE, to make sure
gst_audio_decoder_set_output_format() isn't called again until set_format is called by the base class
*/
if (mpg123_decoder->has_next_audioinfo) {
if (!gst_audio_decoder_set_output_format (dec,
&(mpg123_decoder->next_audioinfo))) {
GstElement *element = GST_ELEMENT (dec);
GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
("Unable to set output format"));
}
mpg123_decoder->has_next_audioinfo = FALSE;
}
break;
case MPG123_NEED_MORE:
case MPG123_OK:
return gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder,
decoded_bytes, num_decoded_bytes);
/* If this happens, then the upstream parser somehow missed the ending of the bitstream */
case MPG123_DONE:
GST_DEBUG_OBJECT (dec, "mpg123 is done decoding");
gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder, decoded_bytes,
num_decoded_bytes);
return GST_FLOW_EOS;
/* Anything else is considered an error */
default:
{
GstElement *element = GST_ELEMENT (dec);
GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL), ("Decoding error: %s",
mpg123_plain_strerror (decode_error)));
return GST_FLOW_ERROR;
}
}
return GST_FLOW_OK;
}
