From 789fc8195ddf2dfd9ec607a195332941a0f8a840 Mon Sep 17 00:00:00 2001 From: Mark Nauwelaerts Date: Mon, 26 Dec 2011 18:24:32 +0100 Subject: [PATCH] lame: ensure parsed output ... by doing some basic parsing of encoded lame data. --- ext/lame/gstlame.c | 234 ++++++++++++++++++++++++++++++++++++++++++++- ext/lame/gstlame.h | 4 + 2 files changed, 234 insertions(+), 4 deletions(-) diff --git a/ext/lame/gstlame.c b/ext/lame/gstlame.c index f36a0b26e5..5387a77c59 100644 --- a/ext/lame/gstlame.c +++ b/ext/lame/gstlame.c @@ -573,6 +573,7 @@ gst_lame_set_format (GstAudioEncoder * enc, GstAudioInfo * info) "output samplerate %d is different from incoming samplerate %d", out_samplerate, lame->samplerate); } + lame->out_samplerate = out_samplerate; version = lame_get_version (lame->lgf); if (version == 0) @@ -663,6 +664,10 @@ gst_lame_start (GstAudioEncoder * enc) { GstLame *lame = GST_LAME (enc); + if (!lame->adapter) + lame->adapter = gst_adapter_new (); + gst_adapter_clear (lame->adapter); + GST_DEBUG_OBJECT (lame, "start"); return TRUE; } @@ -674,6 +679,11 @@ gst_lame_stop (GstAudioEncoder * enc) GST_DEBUG_OBJECT (lame, "stop"); + if (lame->adapter) { + g_object_unref (lame->adapter); + lame->adapter = NULL; + } + gst_lame_release_memory (lame); return TRUE; } @@ -944,12 +954,209 @@ gst_lame_get_property (GObject * object, guint prop_id, GValue * value, } } +/* **** credits go to mpegaudioparse **** */ + +static const guint mp3types_bitrates[2][3][16] = { + { + {0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448,}, + {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384,}, + {0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320,} + }, + { + {0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256,}, + {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160,}, + {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160,} + }, +}; + +static const guint mp3types_freqs[3][3] = { {44100, 48000, 32000}, +{22050, 24000, 16000}, +{11025, 12000, 8000} +}; + +static inline guint +mp3_type_frame_length_from_header (GstLame * lame, guint32 header, + guint * put_version, guint * put_layer, guint * put_channels, + guint * put_bitrate, guint * put_samplerate, guint * put_mode, + guint * put_crc) +{ + guint length; + gulong mode, samplerate, bitrate, layer, channels, padding, crc; + gulong version; + gint lsf, mpg25; + + if (header & (1 << 20)) { + lsf = (header & (1 << 19)) ? 0 : 1; + mpg25 = 0; + } else { + lsf = 1; + mpg25 = 1; + } + + version = 1 + lsf + mpg25; + + layer = 4 - ((header >> 17) & 0x3); + + crc = (header >> 16) & 0x1; + + bitrate = (header >> 12) & 0xF; + bitrate = mp3types_bitrates[lsf][layer - 1][bitrate] * 1000; + /* The caller has ensured we have a valid header, so bitrate can't be + zero here. */ + g_assert (bitrate != 0); + + samplerate = (header >> 10) & 0x3; + samplerate = mp3types_freqs[lsf + mpg25][samplerate]; + + padding = (header >> 9) & 0x1; + + mode = (header >> 6) & 0x3; + channels = (mode == 3) ? 1 : 2; + + switch (layer) { + case 1: + length = 4 * ((bitrate * 12) / samplerate + padding); + break; + case 2: + length = (bitrate * 144) / samplerate + padding; + break; + default: + case 3: + length = (bitrate * 144) / (samplerate << lsf) + padding; + break; + } + + GST_DEBUG_OBJECT (lame, "Calculated mp3 frame length of %u bytes", length); + GST_DEBUG_OBJECT (lame, "samplerate = %lu, bitrate = %lu, version = %lu, " + "layer = %lu, channels = %lu", samplerate, bitrate, version, + layer, channels); + + if (put_version) + *put_version = version; + if (put_layer) + *put_layer = layer; + if (put_channels) + *put_channels = channels; + if (put_bitrate) + *put_bitrate = bitrate; + if (put_samplerate) + *put_samplerate = samplerate; + if (put_mode) + *put_mode = mode; + if (put_crc) + *put_crc = crc; + + return length; +} + +static gboolean +mp3_sync_check (GstLame * lame, unsigned long head) +{ + GST_DEBUG_OBJECT (lame, "checking mp3 header 0x%08lx", head); + /* if it's not a valid sync */ + if ((head & 0xffe00000) != 0xffe00000) { + GST_WARNING_OBJECT (lame, "invalid sync"); + return FALSE; + } + /* if it's an invalid MPEG version */ + if (((head >> 19) & 3) == 0x1) { + GST_WARNING_OBJECT (lame, "invalid MPEG version: 0x%lx", (head >> 19) & 3); + return FALSE; + } + /* if it's an invalid layer */ + if (!((head >> 17) & 3)) { + GST_WARNING_OBJECT (lame, "invalid layer: 0x%lx", (head >> 17) & 3); + return FALSE; + } + /* if it's an invalid bitrate */ + if (((head >> 12) & 0xf) == 0x0) { + GST_WARNING_OBJECT (lame, "invalid bitrate: 0x%lx." + "Free format files are not supported yet", (head >> 12) & 0xf); + return FALSE; + } + if (((head >> 12) & 0xf) == 0xf) { + GST_WARNING_OBJECT (lame, "invalid bitrate: 0x%lx", (head >> 12) & 0xf); + return FALSE; + } + /* if it's an invalid samplerate */ + if (((head >> 10) & 0x3) == 0x3) { + GST_WARNING_OBJECT (lame, "invalid samplerate: 0x%lx", (head >> 10) & 0x3); + return FALSE; + } + + if ((head & 0x3) == 0x2) { + /* Ignore this as there are some files with emphasis 0x2 that can + * be played fine. See BGO #537235 */ + GST_WARNING_OBJECT (lame, "invalid emphasis: 0x%lx", head & 0x3); + } + + return TRUE; +} + +/* **** end mpegaudioparse **** */ + +static GstFlowReturn +gst_lame_finish_frames (GstLame * lame) +{ + gint av; + guint header; + GstFlowReturn result = GST_FLOW_OK; + + /* limited parsing, we don't expect to lose sync here */ + while ((result == GST_FLOW_OK) && + ((av = gst_adapter_available (lame->adapter)) > 4)) { + guint rate, version, layer, size; + GstBuffer *mp3_buf; + const guint8 *data; + + data = gst_adapter_peek (lame->adapter, 4); + header = GST_READ_UINT32_BE (data); + if (!mp3_sync_check (lame, header)) + goto invalid_header; + + size = mp3_type_frame_length_from_header (lame, header, &version, &layer, + NULL, NULL, &rate, NULL, NULL); + + if (G_UNLIKELY (layer != 3 || rate != lame->out_samplerate)) { + GST_DEBUG_OBJECT (lame, + "unexpected mp3 header with (rate, layer): (%u, %u)", + rate, version, layer); + goto invalid_header; + } + + if (size > av) { + /* pretty likely to occur when lame is holding back on us */ + GST_LOG_OBJECT (lame, "frame size %u (> %d)", size, av); + break; + } + + /* should be ok now */ + mp3_buf = gst_adapter_take_buffer (lame->adapter, size); + /* number of samples for MPEG-1, layer 3 */ + result = gst_audio_encoder_finish_frame (GST_AUDIO_ENCODER (lame), + mp3_buf, version == 1 ? 1152 : 576); + } + +exit: + return result; + + /* ERRORS */ +invalid_header: + { + GST_ELEMENT_ERROR (lame, STREAM, ENCODE, + ("invalid lame mp3 sync header %08X", header), (NULL)); + result = GST_FLOW_ERROR; + goto exit; + } +} + static GstFlowReturn gst_lame_flush_full (GstLame * lame, gboolean push) { GstBuffer *buf; gint size; GstFlowReturn result = GST_FLOW_OK; + gint av; if (!lame->lgf) return GST_FLOW_OK; @@ -957,15 +1164,31 @@ gst_lame_flush_full (GstLame * lame, gboolean push) buf = gst_buffer_new_and_alloc (7200); size = lame_encode_flush (lame->lgf, GST_BUFFER_DATA (buf), 7200); - if (size > 0 && push) { + if (size > 0) { GST_BUFFER_SIZE (buf) = size; - GST_DEBUG_OBJECT (lame, "pushing final packet of %u bytes", size); - result = gst_audio_encoder_finish_frame (GST_AUDIO_ENCODER (lame), buf, -1); + GST_DEBUG_OBJECT (lame, "collecting final %d bytes", size); + gst_adapter_push (lame->adapter, buf); } else { GST_DEBUG_OBJECT (lame, "no final packet (size=%d, push=%d)", size, push); gst_buffer_unref (buf); result = GST_FLOW_OK; } + + if (push) { + result = gst_lame_finish_frames (lame); + } else { + /* never mind */ + gst_adapter_clear (lame->adapter); + } + + /* either way, we expect nothing left */ + if ((av = gst_adapter_available (lame->adapter))) { + /* should this be more fatal ?? */ + GST_WARNING_OBJECT (lame, "unparsed %d bytes left after flushing", av); + /* clean up anyway */ + gst_adapter_clear (lame->adapter); + } + return result; } @@ -1023,7 +1246,10 @@ gst_lame_handle_frame (GstAudioEncoder * enc, GstBuffer * buf) if (G_LIKELY (mp3_size > 0)) { GST_BUFFER_SIZE (mp3_buf) = mp3_size; - result = gst_audio_encoder_finish_frame (enc, mp3_buf, -1); + /* unfortunately lame does not provide frame delineated output, + * so collect output and parse into frames ... */ + gst_adapter_push (lame->adapter, mp3_buf); + result = gst_lame_finish_frames (lame); } else { if (mp3_size < 0) { /* eat error ? */ diff --git a/ext/lame/gstlame.h b/ext/lame/gstlame.h index 6755e718aa..f12a47d4f1 100644 --- a/ext/lame/gstlame.h +++ b/ext/lame/gstlame.h @@ -28,6 +28,7 @@ G_BEGIN_DECLS #include #include +#include #define GST_TYPE_LAME \ (gst_lame_get_type()) @@ -54,6 +55,7 @@ struct _GstLame { /*< private >*/ gint samplerate; + gint out_samplerate; gint num_channels; gboolean setup; @@ -91,6 +93,8 @@ struct _GstLame { gint preset; lame_global_flags *lgf; + + GstAdapter *adapter; }; struct _GstLameClass {