avcodec/ac3_parser: handle more header bits in ff_ac3_parse_header()

Based on a patch by nyanmisaka.

James Almer committed 1 year ago

Commit 117343c1 parent efbcd317 files · +282 −221Browse files

Showing the changes to libavcodec (6 of 7 files). Show all

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6 files

libavcodec/ac3_parser.c +219 −0
libavcodec/ac3_parser_internal.h +19 −0
libavcodec/ac3dec.c +20 −68
libavcodec/ac3dec.h +3 −1
libavcodec/ac3defs.h +2 −0
libavcodec/eac3dec.c +17 −137

@@ -73,6 +73,217 @@ int ff_ac3_find_syncword(const uint8_t *buf, int buf_size) · 72 unmodified lines
73	73	return i;
74	74	}
75	75
	76	+/**
	77	+ * Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
	78	+ * GetBitContext within AC3DecodeContext must point to
	79	+ * the start of the synchronized AC-3 bitstream.
	80	+ */
	81	+static int ac3_parse_header(GetBitContext gbc, AC3HeaderInfo hdr)
	82	+{
	83	+ /* read the rest of the bsi. read twice for dual mono mode. */
	84	+ for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
	85	+ hdr->dialog_normalization[i] = -get_bits(gbc, 5);
	86	+ hdr->compression_exists[i] = get_bits1(gbc);
	87	+ if (hdr->compression_exists[i])
	88	+ hdr->heavy_dynamic_range[i] = get_bits(gbc, 8);
	89	+ if (get_bits1(gbc))
	90	+ skip_bits(gbc, 8); //skip language code
	91	+ if (get_bits1(gbc))
	92	+ skip_bits(gbc, 7); //skip audio production information
	93	+ }
	94	+
	95	+ skip_bits(gbc, 2); //skip copyright bit and original bitstream bit
	96	+
	97	+ /* skip the timecodes or parse the Alternate Bit Stream Syntax */
	98	+ if (hdr->bitstream_id != 6) {
	99	+ if (get_bits1(gbc))
	100	+ skip_bits(gbc, 14); //skip timecode1
	101	+ if (get_bits1(gbc))
	102	+ skip_bits(gbc, 14); //skip timecode2
	103	+ } else {
	104	+ if (get_bits1(gbc)) {
	105	+ hdr->preferred_downmix = get_bits(gbc, 2);
	106	+ hdr->center_mix_level_ltrt = get_bits(gbc, 3);
	107	+ hdr->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
	108	+ hdr->center_mix_level = get_bits(gbc, 3);
	109	+ hdr->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
	110	+ }
	111	+ if (get_bits1(gbc)) {
	112	+ hdr->dolby_surround_ex_mode = get_bits(gbc, 2);
	113	+ hdr->dolby_headphone_mode = get_bits(gbc, 2);
	114	+ skip_bits(gbc, 10); // skip adconvtyp (1), xbsi2 (8), encinfo (1)
	115	+ }
	116	+ }
	117	+
	118	+ /* skip additional bitstream info */
	119	+ if (get_bits1(gbc)) {
	120	+ int i = get_bits(gbc, 6);
	121	+ do {
	122	+ skip_bits(gbc, 8);
	123	+ } while (i--);
	124	+ }
	125	+
	126	+ return 0;
	127	+}
	128	+
	129	+static int eac3_parse_header(GetBitContext gbc, AC3HeaderInfo hdr)
	130	+{
	131	+ if (hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
	132	+ return AC3_PARSE_ERROR_FRAME_TYPE;
	133	+ if (hdr->substreamid)
	134	+ return AC3_PARSE_ERROR_FRAME_TYPE;
	135	+
	136	+ skip_bits(gbc, 5); // skip bitstream id
	137	+
	138	+ /* volume control params */
	139	+ for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
	140	+ hdr->dialog_normalization[i] = -get_bits(gbc, 5);
	141	+ hdr->compression_exists[i] = get_bits1(gbc);
	142	+ if (hdr->compression_exists[i])
	143	+ hdr->heavy_dynamic_range[i] = get_bits(gbc, 8);
	144	+ }
	145	+
	146	+ /* dependent stream channel map */
	147	+ if (hdr->frame_type == EAC3_FRAME_TYPE_DEPENDENT) {
	148	+ hdr->channel_map_present = get_bits1(gbc);
	149	+ if (hdr->channel_map_present) {
	150	+ int64_t channel_layout = 0;
	151	+ int channel_map = get_bits(gbc, 16);
	152	+
	153	+ for (int i = 0; i < 16; i++)
	154	+ if (channel_map & (1 << (EAC3_MAX_CHANNELS - i - 1)))
	155	+ channel_layout \|= ff_eac3_custom_channel_map_locations[i][1];
	156	+
	157	+ if (av_popcount64(channel_layout) > EAC3_MAX_CHANNELS) {
	158	+ return AC3_PARSE_ERROR_CHANNEL_MAP;
	159	+ }
	160	+ hdr->channel_map = channel_map;
	161	+ }
	162	+ }
	163	+
	164	+ /* mixing metadata */
	165	+ if (get_bits1(gbc)) {
	166	+ /* center and surround mix levels */
	167	+ if (hdr->channel_mode > AC3_CHMODE_STEREO) {
	168	+ hdr->preferred_downmix = get_bits(gbc, 2);
	169	+ if (hdr->channel_mode & 1) {
	170	+ /* if three front channels exist */
	171	+ hdr->center_mix_level_ltrt = get_bits(gbc, 3);
	172	+ hdr->center_mix_level = get_bits(gbc, 3);
	173	+ }
	174	+ if (hdr->channel_mode & 4) {
	175	+ /* if a surround channel exists */
	176	+ hdr->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
	177	+ hdr->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
	178	+ }
	179	+ }
	180	+
	181	+ /* lfe mix level */
	182	+ if (hdr->lfe_on && (hdr->lfe_mix_level_exists = get_bits1(gbc))) {
	183	+ hdr->lfe_mix_level = get_bits(gbc, 5);
	184	+ }
	185	+
	186	+ /* info for mixing with other streams and substreams */
	187	+ if (hdr->frame_type == EAC3_FRAME_TYPE_INDEPENDENT) {
	188	+ for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
	189	+ // TODO: apply program scale factor
	190	+ if (get_bits1(gbc)) {
	191	+ skip_bits(gbc, 6); // skip program scale factor
	192	+ }
	193	+ }
	194	+ if (get_bits1(gbc)) {
	195	+ skip_bits(gbc, 6); // skip external program scale factor
	196	+ }
	197	+ /* skip mixing parameter data */
	198	+ switch(get_bits(gbc, 2)) {
	199	+ case 1: skip_bits(gbc, 5); break;
	200	+ case 2: skip_bits(gbc, 12); break;
	201	+ case 3: {
	202	+ int mix_data_size = (get_bits(gbc, 5) + 2) << 3;
	203	+ skip_bits_long(gbc, mix_data_size);
	204	+ break;
	205	+ }
	206	+ }
	207	+ /* skip pan information for mono or dual mono source */
	208	+ if (hdr->channel_mode < AC3_CHMODE_STEREO) {
	209	+ for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
	210	+ if (get_bits1(gbc)) {
	211	+ /* note: this is not in the ATSC A/52B specification
	212	+ reference: ETSI TS 102 366 V1.1.1
	213	+ section: E.1.3.1.25 */
	214	+ skip_bits(gbc, 8); // skip pan mean direction index
	215	+ skip_bits(gbc, 6); // skip reserved paninfo bits
	216	+ }
	217	+ }
	218	+ }
	219	+ /* skip mixing configuration information */
	220	+ if (get_bits1(gbc)) {
	221	+ for (int i = 0; i < hdr->num_blocks; i++) {
	222	+ if (hdr->num_blocks == 1 \|\| get_bits1(gbc)) {
	223	+ skip_bits(gbc, 5);
	224	+ }
	225	+ }
	226	+ }
	227	+ }
	228	+ }
	229	+
	230	+ /* informational metadata */
	231	+ if (get_bits1(gbc)) {
	232	+ hdr->bitstream_mode = get_bits(gbc, 3);
	233	+ skip_bits(gbc, 2); // skip copyright bit and original bitstream bit
	234	+ if (hdr->channel_mode == AC3_CHMODE_STEREO) {
	235	+ hdr->dolby_surround_mode = get_bits(gbc, 2);
	236	+ hdr->dolby_headphone_mode = get_bits(gbc, 2);
	237	+ }
	238	+ if (hdr->channel_mode >= AC3_CHMODE_2F2R) {
	239	+ hdr->dolby_surround_ex_mode = get_bits(gbc, 2);
	240	+ }
	241	+ for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
	242	+ if (get_bits1(gbc)) {
	243	+ skip_bits(gbc, 8); // skip mix level, room type, and A/D converter type
	244	+ }
	245	+ }
	246	+ if (hdr->sr_code != EAC3_SR_CODE_REDUCED) {
	247	+ skip_bits1(gbc); // skip source sample rate code
	248	+ }
	249	+ }
	250	+
	251	+ /* converter synchronization flag
	252	+ If frames are less than six blocks, this bit should be turned on
	253	+ once every 6 blocks to indicate the start of a frame set.
	254	+ reference: RFC 4598, Section 2.1.3 Frame Sets */
	255	+ if (hdr->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && hdr->num_blocks != 6) {
	256	+ skip_bits1(gbc); // skip converter synchronization flag
	257	+ }
	258	+
	259	+ /* original frame size code if this stream was converted from AC-3 */
	260	+ if (hdr->frame_type == EAC3_FRAME_TYPE_AC3_CONVERT &&
	261	+ (hdr->num_blocks == 6 \|\| get_bits1(gbc))) {
	262	+ skip_bits(gbc, 6); // skip frame size code
	263	+ }
	264	+
	265	+ /* additional bitstream info */
	266	+ if (get_bits1(gbc)) {
	267	+ int addbsil = get_bits(gbc, 6);
	268	+ for (int i = 0; i < addbsil + 1; i++) {
	269	+ if (i == 0) {
	270	+ /* In this 8 bit chunk, the LSB is equal to flag_ec3_extension_type_a
	271	+ which can be used to detect Atmos presence */
	272	+ skip_bits(gbc, 7);
	273	+ hdr->eac3_extension_type_a = get_bits1(gbc);
	274	+ if (hdr->eac3_extension_type_a) {
	275	+ hdr->complexity_index_type_a = get_bits(gbc, 8);
	276	+ i++;
	277	+ }
	278	+ } else {
	279	+ skip_bits(gbc, 8); // skip additional bit stream info
	280	+ }
	281	+ }
	282	+ }
	283	+
	284	+ return 0;
	285	+}
	286	+
76	287	int ff_ac3_parse_header(GetBitContext gbc, AC3HeaderInfo hdr)
77	288	{
78	289	int frame_size_code;
@@ -133,6 +344,10 @@ int ff_ac3_parse_header(GetBitContext gbc, AC3HeaderInfo hdr) · 54 unmodified lines
133	344	hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
134	345	hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
135	346	hdr->substreamid = 0;
	347	+
	348	+ int ret = ac3_parse_header(gbc, hdr);
	349	+ if (ret < 0)
	350	+ return ret;
136	351	} else {
137	352	/* Enhanced AC-3 */
138	353	hdr->crc1 = 0;
@@ -165,6 +380,10 @@ int ff_ac3_parse_header(GetBitContext gbc, AC3HeaderInfo hdr) · 26 unmodified lines
165	380	hdr->bit_rate = 8LL * hdr->frame_size * hdr->sample_rate /
166	381	(hdr->num_blocks * 256);
167	382	hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
	383	+
	384	+ int ret = eac3_parse_header(gbc, hdr);
	385	+ if (ret < 0)
	386	+ return ret;
168	387	}
169	388	hdr->channel_layout = ff_ac3_channel_layout_tab[hdr->channel_mode];
170	389	if (hdr->lfe_on)

libavcodec/ac3_parser_internal.h+19−0

@@ -46,6 +46,7 @@ typedef struct AC3HeaderInfo { · 45 unmodified lines
46	46	int substreamid; ///< substream identification
47	47	int center_mix_level; ///< Center mix level index
48	48	int surround_mix_level; ///< Surround mix level index
	49	+ uint8_t channel_map_present;
49	50	uint16_t channel_map;
50	51	int num_blocks; ///< number of audio blocks
51	52	int dolby_surround_mode;
@@ -62,6 +63,23 @@ typedef struct AC3HeaderInfo { · 10 unmodified lines
62	63	uint64_t channel_layout;
63	64	int8_t ac3_bit_rate_code;
64	65	/** @} */
	66	+
	67	+ /** @name enhanced eac3 extension coded elements
	68	+ * @{
	69	+ */
	70	+ int8_t dialog_normalization[2];
	71	+ uint8_t compression_exists[2];
	72	+ uint8_t heavy_dynamic_range[2];
	73	+ uint8_t center_mix_level_ltrt; ///< Center mix level index
	74	+ uint8_t surround_mix_level_ltrt; ///< Surround mix level index
	75	+ uint8_t dolby_headphone_mode;
	76	+ uint8_t dolby_surround_ex_mode;
	77	+ uint8_t lfe_mix_level_exists;
	78	+ uint8_t lfe_mix_level;
	79	+ uint8_t preferred_downmix;
	80	+ uint8_t eac3_extension_type_a;
	81	+ uint8_t complexity_index_type_a;
	82	+ /** @} */
65	83	} AC3HeaderInfo;
66	84
67	85	typedef enum {
@@ -71,6 +89,7 @@ typedef enum { · 3 unmodified lines
71	89	AC3_PARSE_ERROR_FRAME_SIZE = -0x4030c0a,
72	90	AC3_PARSE_ERROR_FRAME_TYPE = -0x5030c0a,
73	91	AC3_PARSE_ERROR_CRC = -0x6030c0a,
	92	+ AC3_PARSE_ERROR_CHANNEL_MAP = -0x7030c0a,
74	93	} AC3ParseError;
75	94
76	95	/**

libavcodec/ac3dec.c+20−68

@@ -156,72 +156,6 @@ static av_cold void ac3_decode_flush(AVCodecContext *avctx) · 155 unmodified lines
156	156	av_lfg_init(&s->dith_state, 0);
157	157	}
158	158
159		−/**
160		− * Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
161		− * GetBitContext within AC3DecodeContext must point to
162		− * the start of the synchronized AC-3 bitstream.
163		− */
164		−static int ac3_parse_header(AC3DecodeContext *s)
165		−{
166		− GetBitContext *gbc = &s->gbc;
167		− int i;
168		−
169		− /* read the rest of the bsi. read twice for dual mono mode. */
170		− i = !s->channel_mode;
171		− do {
172		− s->dialog_normalization[(!s->channel_mode)-i] = -get_bits(gbc, 5);
173		− if (s->dialog_normalization[(!s->channel_mode)-i] == 0) {
174		− s->dialog_normalization[(!s->channel_mode)-i] = -31;
175		− }
176		− if (s->target_level != 0) {
177		− s->level_gain[(!s->channel_mode)-i] = powf(2.0f,
178		− (float)(s->target_level -
179		− s->dialog_normalization[(!s->channel_mode)-i])/6.0f);
180		− }
181		− if (s->compression_exists[(!s->channel_mode)-i] = get_bits1(gbc)) {
182		− s->heavy_dynamic_range[(!s->channel_mode)-i] =
183		− AC3_HEAVY_RANGE(get_bits(gbc, 8));
184		− }
185		− if (get_bits1(gbc))
186		− skip_bits(gbc, 8); //skip language code
187		− if (get_bits1(gbc))
188		− skip_bits(gbc, 7); //skip audio production information
189		− } while (i--);
190		−
191		− skip_bits(gbc, 2); //skip copyright bit and original bitstream bit
192		−
193		− /* skip the timecodes or parse the Alternate Bit Stream Syntax */
194		− if (s->bitstream_id != 6) {
195		− if (get_bits1(gbc))
196		− skip_bits(gbc, 14); //skip timecode1
197		− if (get_bits1(gbc))
198		− skip_bits(gbc, 14); //skip timecode2
199		− } else {
200		− if (get_bits1(gbc)) {
201		− s->preferred_downmix = get_bits(gbc, 2);
202		− s->center_mix_level_ltrt = get_bits(gbc, 3);
203		− s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
204		− s->center_mix_level = get_bits(gbc, 3);
205		− s->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
206		− }
207		− if (get_bits1(gbc)) {
208		− s->dolby_surround_ex_mode = get_bits(gbc, 2);
209		− s->dolby_headphone_mode = get_bits(gbc, 2);
210		− skip_bits(gbc, 10); // skip adconvtyp (1), xbsi2 (8), encinfo (1)
211		− }
212		− }
213		−
214		− /* skip additional bitstream info */
215		− if (get_bits1(gbc)) {
216		− i = get_bits(gbc, 6);
217		− do {
218		− skip_bits(gbc, 8);
219		− } while (i--);
220		− }
221		−
222		− return 0;
223		−}
224		−
225	159	/**
226	160	* Common function to parse AC-3 or E-AC-3 frame header
227	161	*/
@@ -281,10 +215,25 @@ static int parse_frame_header(AC3DecodeContext *s) · 53 unmodified lines
281	215	s->dba_syntax = 1;
282	216	s->skip_syntax = 1;
283	217	memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
284		− return ac3_parse_header(s);
	218	+ /* volume control params */
	219	+ for (int i = 0; i < (s->channel_mode ? 1 : 2); i++) {
	220	+ s->dialog_normalization[i] = hdr.dialog_normalization[i];
	221	+ if (s->dialog_normalization[i] == 0) {
	222	+ s->dialog_normalization[i] = -31;
	223	+ }
	224	+ if (s->target_level != 0) {
	225	+ s->level_gain[i] = powf(2.0f,
	226	+ (float)(s->target_level - s->dialog_normalization[i])/6.0f);
	227	+ }
	228	+ s->compression_exists[i] = hdr.compression_exists[i];
	229	+ if (s->compression_exists[i]) {
	230	+ s->heavy_dynamic_range[i] = AC3_HEAVY_RANGE(hdr.heavy_dynamic_range[i]);
	231	+ }
	232	+ }
	233	+ return 0;
285	234	} else if (CONFIG_EAC3_DECODER) {
286	235	s->eac3 = 1;
287		− return ff_eac3_parse_header(s);
	236	+ return ff_eac3_parse_header(s, &hdr);
288	237	} else {
289	238	av_log(s->avctx, AV_LOG_ERROR, "E-AC-3 support not compiled in\n");
290	239	return AVERROR(ENOSYS);
@@ -1469,6 +1418,9 @@ dependent_frame: · 1178 unmodified lines
1469	1418	av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
1470	1419	}
1471	1420	break;
	1421	+ case AC3_PARSE_ERROR_CHANNEL_MAP:
	1422	+ av_log(avctx, AV_LOG_ERROR, "invalid channel map\n");
	1423	+ return AVERROR_INVALIDDATA;
1472	1424	case AC3_PARSE_ERROR_CRC:
1473	1425	break;
1474	1426	default: // Normal AVERROR do not try to recover.

libavcodec/ac3dec.h+3−1

@@ -260,11 +260,13 @@ typedef struct AC3DecodeContext { · 259 unmodified lines
260	260	///@}
261	261	} AC3DecodeContext;
262	262
	263	+struct AC3HeaderInfo;
	264	+
263	265	/**
264	266	* Parse the E-AC-3 frame header.
265	267	* This parses both the bit stream info and audio frame header.
266	268	*/
267		−static int ff_eac3_parse_header(AC3DecodeContext *s);
	269	+static int ff_eac3_parse_header(AC3DecodeContext s, const struct AC3HeaderInfo hdr);
268	270
269	271	/**
270	272	* Decode mantissas in a single channel for the entire frame.

libavcodec/ac3defs.h+2−0

@@ -34,6 +34,8 @@ · 33 unmodified lines
34	34	#define AC3_CRITICAL_BANDS 50
35	35	#define AC3_MAX_CPL_BANDS 18
36	36
	37	+#define EAC3_SR_CODE_REDUCED 3
	38	+
37	39	/* pre-defined gain values */
38	40	#define LEVEL_PLUS_3DB M_SQRT2
39	41	#define LEVEL_PLUS_1POINT5DB 1.1892071150027209

libavcodec/eac3dec.c+17−137

@@ -53,8 +53,6 @@ typedef enum { · 52 unmodified lines
53	53	EAC3_GAQ_124
54	54	} EAC3GaqMode;
55	55
56		−#define EAC3_SR_CODE_REDUCED 3
57		−
58	56	static void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
59	57	{
60	58	int bin, bnd, ch, i;
@@ -287,7 +285,7 @@ static void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch) · 226 unmodified lines
287	285	}
288	286	}
289	287
290		−static int ff_eac3_parse_header(AC3DecodeContext *s)
	288	+static int ff_eac3_parse_header(AC3DecodeContext s, const AC3HeaderInfo hdr)
291	289	{
292	290	int i, blk, ch;
293	291	int ac3_exponent_strategy, parse_aht_info, parse_spx_atten_data;
@@ -323,11 +321,10 @@ static int ff_eac3_parse_header(AC3DecodeContext *s) · 29 unmodified lines
323	321	avpriv_request_sample(s->avctx, "Reduced sampling rate");
324	322	return AVERROR_PATCHWELCOME;
325	323	}
326		− skip_bits(gbc, 5); // skip bitstream id
327	324
328	325	/* volume control params */
329	326	for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
330		− s->dialog_normalization[i] = -get_bits(gbc, 5);
	327	+ s->dialog_normalization[i] = hdr->dialog_normalization[i];
331	328	if (s->dialog_normalization[i] == 0) {
332	329	s->dialog_normalization[i] = -31;
333	330	}
@@ -335,147 +332,30 @@ static int ff_eac3_parse_header(AC3DecodeContext *s) · 1 unmodified line
335	332	s->level_gain[i] = powf(2.0f,
336	333	(float)(s->target_level - s->dialog_normalization[i])/6.0f);
337	334	}
338		− s->compression_exists[i] = get_bits1(gbc);
339		− if (s->compression_exists[i]) {
340		− s->heavy_dynamic_range[i] = AC3_HEAVY_RANGE(get_bits(gbc, 8));
	335	+ if (hdr->compression_exists[i]) {
	336	+ s->heavy_dynamic_range[i] = AC3_HEAVY_RANGE(hdr->heavy_dynamic_range[i]);
341	337	}
342	338	}
343	339
344		− /* dependent stream channel map */
345		− if (s->frame_type == EAC3_FRAME_TYPE_DEPENDENT) {
346		− if (get_bits1(gbc)) {
347		− int64_t channel_layout = 0;
348		− int channel_map = get_bits(gbc, 16);
349		− av_log(s->avctx, AV_LOG_DEBUG, "channel_map: %0X\n", channel_map);
350		−
351		− for (i = 0; i < 16; i++)
352		− if (channel_map & (1 << (EAC3_MAX_CHANNELS - i - 1)))
353		− channel_layout \|= ff_eac3_custom_channel_map_locations[i][1];
354		−
355		− if (av_popcount64(channel_layout) > EAC3_MAX_CHANNELS) {
356		− return AVERROR_INVALIDDATA;
357		− }
358		− s->channel_map = channel_map;
359		− }
360		− }
	340	+ s->channel_map = hdr->channel_map;
361	341
362	342	/* mixing metadata */
363		− if (get_bits1(gbc)) {
364		− /* center and surround mix levels */
365		− if (s->channel_mode > AC3_CHMODE_STEREO) {
366		− s->preferred_downmix = get_bits(gbc, 2);
367		− if (s->channel_mode & 1) {
368		− /* if three front channels exist */
369		− s->center_mix_level_ltrt = get_bits(gbc, 3);
370		− s->center_mix_level = get_bits(gbc, 3);
371		− }
372		− if (s->channel_mode & 4) {
373		− /* if a surround channel exists */
374		− s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
375		− s->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
376		− }
377		− }
378		−
379		− /* lfe mix level */
380		− if (s->lfe_on && (s->lfe_mix_level_exists = get_bits1(gbc))) {
381		− s->lfe_mix_level = get_bits(gbc, 5);
382		− }
383		−
384		− /* info for mixing with other streams and substreams */
385		− if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT) {
386		− for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
387		− // TODO: apply program scale factor
388		− if (get_bits1(gbc)) {
389		− skip_bits(gbc, 6); // skip program scale factor
390		− }
391		− }
392		− if (get_bits1(gbc)) {
393		− skip_bits(gbc, 6); // skip external program scale factor
394		− }
395		− /* skip mixing parameter data */
396		− switch(get_bits(gbc, 2)) {
397		− case 1: skip_bits(gbc, 5); break;
398		− case 2: skip_bits(gbc, 12); break;
399		− case 3: {
400		− int mix_data_size = (get_bits(gbc, 5) + 2) << 3;
401		− skip_bits_long(gbc, mix_data_size);
402		− break;
403		− }
404		− }
405		− /* skip pan information for mono or dual mono source */
406		− if (s->channel_mode < AC3_CHMODE_STEREO) {
407		− for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
408		− if (get_bits1(gbc)) {
409		− /* note: this is not in the ATSC A/52B specification
410		− reference: ETSI TS 102 366 V1.1.1
411		− section: E.1.3.1.25 */
412		− skip_bits(gbc, 8); // skip pan mean direction index
413		− skip_bits(gbc, 6); // skip reserved paninfo bits
414		− }
415		− }
416		− }
417		− /* skip mixing configuration information */
418		− if (get_bits1(gbc)) {
419		− for (blk = 0; blk < s->num_blocks; blk++) {
420		− if (s->num_blocks == 1 \|\| get_bits1(gbc)) {
421		− skip_bits(gbc, 5);
422		− }
423		− }
424		− }
425		− }
426		− }
	343	+ s->preferred_downmix = hdr->preferred_downmix;
	344	+ s->center_mix_level_ltrt = hdr->center_mix_level_ltrt;
	345	+ s->center_mix_level = hdr->center_mix_level;
	346	+ s->surround_mix_level_ltrt = hdr->surround_mix_level_ltrt;
	347	+ s->surround_mix_level = hdr->surround_mix_level;
	348	+ s->lfe_mix_level_exists = hdr->lfe_mix_level_exists;
	349	+ s->lfe_mix_level = hdr->lfe_mix_level;
	350	+ s->dolby_surround_mode = hdr->dolby_surround_mode;
	351	+ s->dolby_headphone_mode = hdr->dolby_headphone_mode;
	352	+ s->dolby_surround_ex_mode = hdr->dolby_surround_ex_mode;
427	353
428	354	/* informational metadata */
429		− if (get_bits1(gbc)) {
430		− s->bitstream_mode = get_bits(gbc, 3);
431		− skip_bits(gbc, 2); // skip copyright bit and original bitstream bit
432		− if (s->channel_mode == AC3_CHMODE_STEREO) {
433		− s->dolby_surround_mode = get_bits(gbc, 2);
434		− s->dolby_headphone_mode = get_bits(gbc, 2);
435		− }
436		− if (s->channel_mode >= AC3_CHMODE_2F2R) {
437		− s->dolby_surround_ex_mode = get_bits(gbc, 2);
438		− }
439		− for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
440		− if (get_bits1(gbc)) {
441		− skip_bits(gbc, 8); // skip mix level, room type, and A/D converter type
442		− }
443		− }
444		− if (s->bit_alloc_params.sr_code != EAC3_SR_CODE_REDUCED) {
445		− skip_bits1(gbc); // skip source sample rate code
446		− }
447		− }
448		−
449		− /* converter synchronization flag
450		− If frames are less than six blocks, this bit should be turned on
451		− once every 6 blocks to indicate the start of a frame set.
452		− reference: RFC 4598, Section 2.1.3 Frame Sets */
453		− if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && s->num_blocks != 6) {
454		− skip_bits1(gbc); // skip converter synchronization flag
455		− }
456		−
457		− /* original frame size code if this stream was converted from AC-3 */
458		− if (s->frame_type == EAC3_FRAME_TYPE_AC3_CONVERT &&
459		− (s->num_blocks == 6 \|\| get_bits1(gbc))) {
460		− skip_bits(gbc, 6); // skip frame size code
461		− }
	355	+ s->bitstream_mode = hdr->bitstream_mode;
462	356
463	357	/* additional bitstream info */
464		− if (get_bits1(gbc)) {
465		− int addbsil = get_bits(gbc, 6);
466		− for (i = 0; i < addbsil + 1; i++) {
467		− if (i == 0) {
468		− /* In this 8 bit chunk, the LSB is equal to flag_ec3_extension_type_a
469		− which can be used to detect Atmos presence */
470		− skip_bits(gbc, 7);
471		− if (get_bits1(gbc)) {
472		− s->eac3_extension_type_a = 1;
473		− }
474		− } else {
475		− skip_bits(gbc, 8); // skip additional bit stream info
476		− }
477		− }
478		− }
	358	+ s->eac3_extension_type_a = hdr->eac3_extension_type_a;
479	359
480	360	/* audio frame syntax flags, strategy data, and per-frame data */
481	361

avcodec/ac3_parser: handle more header bits in ff_ac3_parse_header()

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