diff options
Diffstat (limited to 'src/audio_dec/xine_mad_decoder.c')
| -rw-r--r-- | src/audio_dec/xine_mad_decoder.c | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/src/audio_dec/xine_mad_decoder.c b/src/audio_dec/xine_mad_decoder.c index de7590f4e..74c04924f 100644 --- a/src/audio_dec/xine_mad_decoder.c +++ b/src/audio_dec/xine_mad_decoder.c @@ -48,6 +48,20 @@ #define INPUT_BUF_SIZE 16384 +/* According to Rob Leslie (libmad author) : + * The absolute theoretical maximum frame size is 2881 bytes: MPEG 2.5 Layer II, + * 8000 Hz @ 160 kbps, with a padding slot. (Such a frame is unlikely, but it was + * a useful exercise to compute all possible frame sizes.) Add to this an 8 byte + * MAD_BUFFER_GUARD, and the minimum buffer size you should be streaming to + * libmad in the general case is 2889 bytes. + + * Theoretical frame sizes for Layer III range from 24 to 1441 bytes, but there + * is a "soft" limit imposed by the standard of 960 bytes. Nonetheless MAD can + * decode frames of any size as long as they fit entirely in the buffer you pass, + * not including the MAD_BUFFER_GUARD bytes. + */ +#define MAD_MIN_SIZE 2889 + typedef struct { audio_decoder_class_t decoder_class; } mad_class_t; @@ -135,9 +149,10 @@ static int head_check(mad_decoder_t *this) { static void mad_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) { mad_decoder_t *this = (mad_decoder_t *) this_gen; + int bytes_in_buffer_at_pts; + + lprintf ("decode data, size: %d, decoder_flags: %d\n", buf->size, buf->decoder_flags); - lprintf ("decode data, decoder_flags: %d\n", buf->decoder_flags); - if (buf->size>(INPUT_BUF_SIZE-this->bytes_in_buffer)) { xprintf (this->xstream->xine, XINE_VERBOSITY_DEBUG, "libmad: ALERT input buffer too small (%d bytes, %d avail)!\n", @@ -156,6 +171,8 @@ static void mad_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) { this->preview_mode = 1; } + bytes_in_buffer_at_pts = this->bytes_in_buffer; + xine_fast_memcpy (&this->buffer[this->bytes_in_buffer], buf->content, buf->size); this->bytes_in_buffer += buf->size; @@ -167,6 +184,9 @@ static void mad_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) { mad_stream_buffer (&this->stream, this->buffer, this->bytes_in_buffer); + if (this->bytes_in_buffer < MAD_MIN_SIZE) + return; + while (1) { if (mad_frame_decode (&this->frame, &this->stream) != 0) { @@ -187,6 +207,7 @@ static void mad_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) { return; default: + lprintf ("error 0x%04X, mad_stream_buffer %d bytes\n", this->stream.error, this->bytes_in_buffer); mad_stream_buffer (&this->stream, this->buffer, this->bytes_in_buffer); } @@ -253,6 +274,8 @@ static void mad_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) { struct mad_pcm *pcm = &this->synth.pcm; audio_buffer_t *audio_buffer; uint16_t *output; + int bitrate; + int pts_offset; audio_buffer = this->xstream->audio_out->get_buffer (this->xstream->audio_out); output = audio_buffer->mem; @@ -273,7 +296,22 @@ static void mad_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) { } audio_buffer->num_frames = pcm->length; - audio_buffer->vpts = buf->pts; + + /* pts computing */ + if (this->frame.header.bitrate > 0) { + bitrate = this->frame.header.bitrate; + } else { + bitrate = _x_stream_info_get(this->xstream, XINE_STREAM_INFO_AUDIO_BITRATE); + lprintf("offset %d bps\n", bitrate); + } + audio_buffer->vpts = buf->pts; + if (audio_buffer->vpts && (bitrate > 0)) { + pts_offset = (bytes_in_buffer_at_pts * 8 * 90) / (bitrate / 1000); + lprintf("pts: %"PRId64", offset: %d pts, %d bytes\n", buf->pts, pts_offset, bytes_in_buffer_at_pts); + if (audio_buffer->vpts < pts_offset) + pts_offset = audio_buffer->vpts; + audio_buffer->vpts -= pts_offset; + } this->xstream->audio_out->put_buffer (this->xstream->audio_out, audio_buffer, this->xstream); |