[FFmpeg-cvslog] avcodec/aacdec: refactor the channel layout derivation code
James Almer
git at videolan.org
Fri Nov 4 00:45:16 EET 2022
ffmpeg | branch: master | James Almer <jamrial at gmail.com> | Fri Oct 28 18:27:58 2022 -0300| [828b0da7b772fe60b9087d30c2da55efde09d625] | committer: James Almer
avcodec/aacdec: refactor the channel layout derivation code
Generalize the checks for channels in all positions, and properly support
the three height groups (normal, top, bottom) instead of manually setting
the relevant channels for the latter two after the normal height tags were
parsed.
Signed-off-by: James Almer <jamrial at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=828b0da7b772fe60b9087d30c2da55efde09d625
---
libavcodec/aacdec_template.c | 256 ++++++++++++++-----------------------------
libavcodec/aacdectab.h | 27 ++++-
2 files changed, 107 insertions(+), 176 deletions(-)
diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index 4a88aeae1d..72c3fbe6b8 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -238,13 +238,13 @@ static int assign_pair(struct elem_to_channel e2c_vec[MAX_ELEM_ID],
}
static int count_paired_channels(uint8_t (*layout_map)[3], int tags, int pos,
- int *current)
+ int current)
{
int num_pos_channels = 0;
int first_cpe = 0;
int sce_parity = 0;
int i;
- for (i = *current; i < tags; i++) {
+ for (i = current; i < tags; i++) {
if (layout_map[i][2] != pos)
break;
if (layout_map[i][0] == TYPE_CPE) {
@@ -259,207 +259,117 @@ static int count_paired_channels(uint8_t (*layout_map)[3], int tags, int pos,
first_cpe = 1;
} else {
num_pos_channels++;
- sce_parity ^= 1;
+ sce_parity ^= (pos != AAC_CHANNEL_LFE);
}
}
if (sce_parity &&
- ((pos == AAC_CHANNEL_FRONT && first_cpe) || pos == AAC_CHANNEL_SIDE))
+ (pos == AAC_CHANNEL_FRONT && first_cpe))
return -1;
- *current = i;
+
return num_pos_channels;
}
-#define PREFIX_FOR_22POINT2 (AV_CH_LAYOUT_7POINT1_WIDE_BACK|AV_CH_BACK_CENTER|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT|AV_CH_LOW_FREQUENCY_2)
-static uint64_t sniff_channel_order(uint8_t (*layout_map)[3], int tags)
+static int assign_channels(struct elem_to_channel e2c_vec[MAX_ELEM_ID], uint8_t (*layout_map)[3],
+ uint64_t *layout, int tags, int layer, int pos, int *current)
{
- int i, n, total_non_cc_elements;
- struct elem_to_channel e2c_vec[4 * MAX_ELEM_ID] = { { 0 } };
- int num_front_channels, num_side_channels, num_back_channels;
- uint64_t layout = 0;
+ int i = *current, j = 0;
+ int nb_channels = count_paired_channels(layout_map, tags, pos, i);
- if (FF_ARRAY_ELEMS(e2c_vec) < tags)
+ if (nb_channels < 0 || nb_channels > 5)
return 0;
- i = 0;
- num_front_channels =
- count_paired_channels(layout_map, tags, AAC_CHANNEL_FRONT, &i);
- if (num_front_channels < 0)
- return 0;
- num_side_channels =
- count_paired_channels(layout_map, tags, AAC_CHANNEL_SIDE, &i);
- if (num_side_channels < 0)
- return 0;
- num_back_channels =
- count_paired_channels(layout_map, tags, AAC_CHANNEL_BACK, &i);
- if (num_back_channels < 0)
- return 0;
+ if (pos == AAC_CHANNEL_LFE) {
+ while (nb_channels) {
+ if (aac_channel_map[layer][pos - 1][j] == AV_CHAN_NONE)
+ return -1;
+ e2c_vec[i] = (struct elem_to_channel) {
+ .av_position = 1ULL << aac_channel_map[layer][pos - 1][j],
+ .syn_ele = layout_map[i][0],
+ .elem_id = layout_map[i][1],
+ .aac_position = pos
+ };
+ *layout |= e2c_vec[i].av_position;
+ i++;
+ j++;
+ nb_channels--;
+ }
+ *current = i;
- if (num_side_channels == 0 && num_back_channels >= 4) {
- num_side_channels = 2;
- num_back_channels -= 2;
+ return 0;
}
- i = 0;
- if (num_front_channels & 1) {
+ while (nb_channels & 1) {
+ if (aac_channel_map[layer][pos - 1][0] == AV_CHAN_NONE)
+ return -1;
+ if (aac_channel_map[layer][pos - 1][0] == AV_CHAN_UNUSED)
+ break;
e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_FRONT_CENTER,
- .syn_ele = TYPE_SCE,
+ .av_position = 1ULL << aac_channel_map[layer][pos - 1][0],
+ .syn_ele = layout_map[i][0],
.elem_id = layout_map[i][1],
- .aac_position = AAC_CHANNEL_FRONT
+ .aac_position = pos
};
- layout |= e2c_vec[i].av_position;
+ *layout |= e2c_vec[i].av_position;
i++;
- num_front_channels--;
+ nb_channels--;
}
- if (num_front_channels >= 4) {
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_FRONT_LEFT_OF_CENTER,
- AV_CH_FRONT_RIGHT_OF_CENTER,
- AAC_CHANNEL_FRONT, &layout);
- num_front_channels -= 2;
- }
- if (num_front_channels >= 2) {
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_FRONT_LEFT,
- AV_CH_FRONT_RIGHT,
- AAC_CHANNEL_FRONT, &layout);
- num_front_channels -= 2;
- }
- if (num_front_channels)
- return 0; // Non standard PCE defined layout
- if (num_side_channels >= 2) {
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_SIDE_LEFT,
- AV_CH_SIDE_RIGHT,
- AAC_CHANNEL_SIDE, &layout);
- num_side_channels -= 2;
- }
- if (num_side_channels)
- return 0; // Non standard PCE defined layout
-
- if (num_back_channels >= 2) {
+ j = (pos != AAC_CHANNEL_SIDE) && nb_channels <= 3 ? 3 : 1;
+ while (nb_channels >= 2) {
+ if (aac_channel_map[layer][pos - 1][j] == AV_CHAN_NONE ||
+ aac_channel_map[layer][pos - 1][j+1] == AV_CHAN_NONE)
+ return -1;
i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_BACK_LEFT,
- AV_CH_BACK_RIGHT,
- AAC_CHANNEL_BACK, &layout);
- num_back_channels -= 2;
- }
- if (num_back_channels) {
+ 1ULL << aac_channel_map[layer][pos - 1][j],
+ 1ULL << aac_channel_map[layer][pos - 1][j+1],
+ pos, layout);
+ j += 2;
+ nb_channels -= 2;
+ }
+ while (nb_channels & 1) {
+ if (aac_channel_map[layer][pos - 1][5] == AV_CHAN_NONE)
+ return -1;
e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_BACK_CENTER,
- .syn_ele = TYPE_SCE,
+ .av_position = 1ULL << aac_channel_map[layer][pos - 1][5],
+ .syn_ele = layout_map[i][0],
.elem_id = layout_map[i][1],
- .aac_position = AAC_CHANNEL_BACK
+ .aac_position = pos
};
- layout |= e2c_vec[i].av_position;
+ *layout |= e2c_vec[i].av_position;
i++;
- num_back_channels--;
+ nb_channels--;
}
- if (num_back_channels)
- return 0; // Non standard PCE defined layout
+ if (nb_channels)
+ return -1;
- if (i < tags && layout_map[i][2] == AAC_CHANNEL_LFE) {
- e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_LOW_FREQUENCY,
- .syn_ele = TYPE_LFE,
- .elem_id = layout_map[i][1],
- .aac_position = AAC_CHANNEL_LFE
- };
- layout |= e2c_vec[i].av_position;
- i++;
- }
- if (i < tags && layout_map[i][2] == AAC_CHANNEL_LFE) {
- e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_LOW_FREQUENCY_2,
- .syn_ele = TYPE_LFE,
- .elem_id = layout_map[i][1],
- .aac_position = AAC_CHANNEL_LFE
- };
- layout |= e2c_vec[i].av_position;
- i++;
- }
- while (i < tags && layout_map[i][2] == AAC_CHANNEL_LFE) {
- e2c_vec[i] = (struct elem_to_channel) {
- .av_position = UINT64_MAX,
- .syn_ele = TYPE_LFE,
- .elem_id = layout_map[i][1],
- .aac_position = AAC_CHANNEL_LFE
- };
- i++;
- }
+ *current = i;
- // The previous checks would end up at 4 at this point for chan_config 14
- if (layout == AV_CH_LAYOUT_5POINT1_BACK && tags == 5 && i == 4) {
- const uint8_t (*reference_layout_map)[3] = aac_channel_layout_map[13];
- for (int j = 0; j < tags; j++) {
- if (layout_map[j][0] != reference_layout_map[j][0] ||
- layout_map[j][2] != reference_layout_map[j][2])
- goto end_of_layout_definition;
- }
+ return 0;
+}
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_TOP_FRONT_LEFT,
- AV_CH_TOP_FRONT_RIGHT,
- AAC_CHANNEL_FRONT,
- &layout);
- }
- // The previous checks would end up at 8 at this point for 22.2
- if (layout == PREFIX_FOR_22POINT2 && tags == 16 && i == 8) {
- const uint8_t (*reference_layout_map)[3] = aac_channel_layout_map[12];
- for (int j = 0; j < tags; j++) {
- if (layout_map[j][0] != reference_layout_map[j][0] ||
- layout_map[j][2] != reference_layout_map[j][2])
- goto end_of_layout_definition;
- }
+static uint64_t sniff_channel_order(uint8_t (*layout_map)[3], int tags)
+{
+ int i, n, total_non_cc_elements;
+ struct elem_to_channel e2c_vec[4 * MAX_ELEM_ID] = { { 0 } };
+ uint64_t layout = 0;
- e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_TOP_FRONT_CENTER,
- .syn_ele = layout_map[i][0],
- .elem_id = layout_map[i][1],
- .aac_position = layout_map[i][2]
- }; layout |= e2c_vec[i].av_position; i++;
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_TOP_FRONT_LEFT,
- AV_CH_TOP_FRONT_RIGHT,
- AAC_CHANNEL_FRONT,
- &layout);
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_TOP_SIDE_LEFT,
- AV_CH_TOP_SIDE_RIGHT,
- AAC_CHANNEL_SIDE,
- &layout);
- e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_TOP_CENTER,
- .syn_ele = layout_map[i][0],
- .elem_id = layout_map[i][1],
- .aac_position = layout_map[i][2]
- }; layout |= e2c_vec[i].av_position; i++;
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_TOP_BACK_LEFT,
- AV_CH_TOP_BACK_RIGHT,
- AAC_CHANNEL_BACK,
- &layout);
- e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_TOP_BACK_CENTER,
- .syn_ele = layout_map[i][0],
- .elem_id = layout_map[i][1],
- .aac_position = layout_map[i][2]
- }; layout |= e2c_vec[i].av_position; i++;
- e2c_vec[i] = (struct elem_to_channel) {
- .av_position = AV_CH_BOTTOM_FRONT_CENTER,
- .syn_ele = layout_map[i][0],
- .elem_id = layout_map[i][1],
- .aac_position = layout_map[i][2]
- }; layout |= e2c_vec[i].av_position; i++;
- i += assign_pair(e2c_vec, layout_map, i,
- AV_CH_BOTTOM_FRONT_LEFT,
- AV_CH_BOTTOM_FRONT_RIGHT,
- AAC_CHANNEL_FRONT,
- &layout);
- }
+ if (FF_ARRAY_ELEMS(e2c_vec) < tags)
+ return 0;
-end_of_layout_definition:
+ for (n = 0, i = 0; n < 3 && i < tags; n++) {
+ int ret = assign_channels(e2c_vec, layout_map, &layout, tags, n, AAC_CHANNEL_FRONT, &i);
+ if (ret < 0)
+ return 0;
+ ret = assign_channels(e2c_vec, layout_map, &layout, tags, n, AAC_CHANNEL_SIDE, &i);
+ if (ret < 0)
+ return 0;
+ ret = assign_channels(e2c_vec, layout_map, &layout, tags, n, AAC_CHANNEL_BACK, &i);
+ if (ret < 0)
+ return 0;
+ ret = assign_channels(e2c_vec, layout_map, &layout, tags, n, AAC_CHANNEL_LFE, &i);
+ if (ret < 0)
+ return 0;
+ }
total_non_cc_elements = n = i;
@@ -655,7 +565,7 @@ static int set_default_channel_config(AACContext *ac, AVCodecContext *avctx,
* 7.1 layout was intended.
*/
if (channel_config == 7 && avctx->strict_std_compliance < FF_COMPLIANCE_STRICT) {
- layout_map[2][2] = AAC_CHANNEL_SIDE;
+ layout_map[2][2] = AAC_CHANNEL_BACK;
if (!ac || !ac->warned_71_wide++) {
av_log(avctx, AV_LOG_INFO, "Assuming an incorrectly encoded 7.1 channel layout"
diff --git a/libavcodec/aacdectab.h b/libavcodec/aacdectab.h
index 0e5e47da64..41f1db781d 100644
--- a/libavcodec/aacdectab.h
+++ b/libavcodec/aacdectab.h
@@ -49,12 +49,12 @@ static const uint8_t aac_channel_layout_map[16][16][3] = {
{ { 0, } },
{ { 0, } },
{ { TYPE_SCE, 0, AAC_CHANNEL_FRONT }, { TYPE_CPE, 0, AAC_CHANNEL_FRONT }, { TYPE_CPE, 1, AAC_CHANNEL_BACK }, { TYPE_SCE, 1, AAC_CHANNEL_BACK }, { TYPE_LFE, 0, AAC_CHANNEL_LFE }, },
- { { TYPE_SCE, 0, AAC_CHANNEL_FRONT }, { TYPE_CPE, 0, AAC_CHANNEL_FRONT }, { TYPE_CPE, 1, AAC_CHANNEL_SIDE }, { TYPE_CPE, 2, AAC_CHANNEL_BACK }, { TYPE_LFE, 0, AAC_CHANNEL_LFE }, },
+ { { TYPE_SCE, 0, AAC_CHANNEL_FRONT }, { TYPE_CPE, 0, AAC_CHANNEL_FRONT }, { TYPE_CPE, 1, AAC_CHANNEL_BACK }, { TYPE_CPE, 2, AAC_CHANNEL_BACK }, { TYPE_LFE, 0, AAC_CHANNEL_LFE }, },
{
{ TYPE_SCE, 0, AAC_CHANNEL_FRONT }, // SCE1 = FC,
{ TYPE_CPE, 0, AAC_CHANNEL_FRONT }, // CPE1 = FLc and FRc,
{ TYPE_CPE, 1, AAC_CHANNEL_FRONT }, // CPE2 = FL and FR,
- { TYPE_CPE, 2, AAC_CHANNEL_SIDE }, // CPE3 = SiL and SiR,
+ { TYPE_CPE, 2, AAC_CHANNEL_BACK }, // CPE3 = SiL and SiR,
{ TYPE_CPE, 3, AAC_CHANNEL_BACK }, // CPE4 = BL and BR,
{ TYPE_SCE, 1, AAC_CHANNEL_BACK }, // SCE2 = BC,
{ TYPE_LFE, 0, AAC_CHANNEL_LFE }, // LFE1 = LFE1,
@@ -62,7 +62,7 @@ static const uint8_t aac_channel_layout_map[16][16][3] = {
{ TYPE_SCE, 2, AAC_CHANNEL_FRONT }, // SCE3 = TpFC,
{ TYPE_CPE, 4, AAC_CHANNEL_FRONT }, // CPE5 = TpFL and TpFR,
{ TYPE_CPE, 5, AAC_CHANNEL_SIDE }, // CPE6 = TpSiL and TpSiR,
- { TYPE_SCE, 3, AAC_CHANNEL_FRONT }, // SCE4 = TpC,
+ { TYPE_SCE, 3, AAC_CHANNEL_SIDE }, // SCE4 = TpC,
{ TYPE_CPE, 6, AAC_CHANNEL_BACK }, // CPE7 = TpBL and TpBR,
{ TYPE_SCE, 4, AAC_CHANNEL_BACK }, // SCE5 = TpBC,
{ TYPE_SCE, 5, AAC_CHANNEL_FRONT }, // SCE6 = BtFC,
@@ -72,6 +72,27 @@ static const uint8_t aac_channel_layout_map[16][16][3] = {
{ { 0, } },
};
+static const int16_t aac_channel_map[3][4][6] = {
+ {
+ { AV_CHAN_FRONT_CENTER, AV_CHAN_FRONT_LEFT_OF_CENTER, AV_CHAN_FRONT_RIGHT_OF_CENTER, AV_CHAN_FRONT_LEFT, AV_CHAN_FRONT_RIGHT, AV_CHAN_NONE },
+ { AV_CHAN_UNUSED, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE },
+ { AV_CHAN_UNUSED, AV_CHAN_SIDE_LEFT, AV_CHAN_SIDE_RIGHT, AV_CHAN_BACK_LEFT, AV_CHAN_BACK_RIGHT, AV_CHAN_BACK_CENTER },
+ { AV_CHAN_LOW_FREQUENCY, AV_CHAN_LOW_FREQUENCY_2, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE },
+ },
+ {
+ { AV_CHAN_TOP_FRONT_CENTER, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_TOP_FRONT_LEFT, AV_CHAN_TOP_FRONT_RIGHT, AV_CHAN_NONE },
+ { AV_CHAN_UNUSED, AV_CHAN_TOP_SIDE_LEFT, AV_CHAN_TOP_SIDE_RIGHT, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_TOP_CENTER},
+ { AV_CHAN_UNUSED, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_TOP_BACK_LEFT, AV_CHAN_TOP_BACK_RIGHT, AV_CHAN_TOP_BACK_CENTER},
+ { AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE},
+ },
+ {
+ { AV_CHAN_BOTTOM_FRONT_CENTER, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_BOTTOM_FRONT_LEFT, AV_CHAN_BOTTOM_FRONT_RIGHT, AV_CHAN_NONE },
+ { AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE },
+ { AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE },
+ { AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE, AV_CHAN_NONE },
+ },
+};
+
#if FF_API_OLD_CHANNEL_LAYOUT
static const uint64_t aac_channel_layout[] = {
AV_CH_LAYOUT_MONO,
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