avcodec: add FTR audio decoder and parser

1 files changed, 107 insertions, 0 deletions

diff --git a/libavcodec/ftr_parser.c b/libavcodec/ftr_parser.c
new file mode 100644
index 0000000000..05e6cfed98
--- /dev/null
+++ b/libavcodec/ftr_parser.c
@@ -0,0 +1,107 @@
+/*
+ * FTR parser
+ * Copyright (c) 2022 Paul B Mahol
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * FTR parser
+ */
+
+#include "parser.h"
+#include "get_bits.h"
+#include "adts_header.h"
+#include "adts_parser.h"
+#include "mpeg4audio.h"
+
+typedef struct FTRParseContext {
+    ParseContext pc;
+    int skip;
+    int split;
+    int frame_index;
+} FTRParseContext;
+
+static int ftr_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+                     const uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size)
+{
+    uint8_t tmp[8 + AV_INPUT_BUFFER_PADDING_SIZE];
+    FTRParseContext *ftr = s->priv_data;
+    uint64_t state = ftr->pc.state64;
+    int next = END_NOT_FOUND;
+    GetBitContext bits;
+    AACADTSHeaderInfo hdr;
+    int size;
+
+    *poutbuf_size = 0;
+    *poutbuf = NULL;
+
+    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
+        next = buf_size;
+    } else {
+        for (int i = 0; i < buf_size; i++) {
+            if (ftr->skip > 0) {
+                ftr->skip--;
+                if (ftr->skip == 0 && ftr->split) {
+                    ftr->split = 0;
+                    next = i;
+                    s->duration = 1024;
+                    s->key_frame = 1;
+                    break;
+                } else if (ftr->skip > 0) {
+                    continue;
+                }
+            }
+
+            state = (state << 8) | buf[i];
+            AV_WB64(tmp, state);
+            init_get_bits(&bits, tmp + 8 - AV_AAC_ADTS_HEADER_SIZE,
+                          AV_AAC_ADTS_HEADER_SIZE * 8);
+
+            if ((size = ff_adts_header_parse(&bits, &hdr)) > 0) {
+                ftr->skip = size - 6;
+                ftr->frame_index += ff_mpeg4audio_channels[hdr.chan_config];
+                if (ftr->frame_index >= avctx->ch_layout.nb_channels) {
+                    ftr->frame_index = 0;
+                    ftr->split = 1;
+                }
+            }
+        }
+
+        ftr->pc.state64 = state;
+
+        if (ff_combine_frame(&ftr->pc, next, &buf, &buf_size) < 0) {
+            *poutbuf = NULL;
+            *poutbuf_size = 0;
+            return buf_size;
+        }
+    }
+
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+
+    return next;
+}
+
+const AVCodecParser ff_ftr_parser = {
+    .codec_ids      = { AV_CODEC_ID_FTR },
+    .priv_data_size = sizeof(FTRParseContext),
+    .parser_parse   = ftr_parse,
+    .parser_close   = ff_parse_close,
+};