avcodec: add FTR audio decoder and parser

1 files changed, 208 insertions, 0 deletions

diff --git a/libavcodec/ftr.c b/libavcodec/ftr.c
new file mode 100644
index 0000000000..277b9be5b8
--- /dev/null
+++ b/libavcodec/ftr.c
@@ -0,0 +1,208 @@
+/*
+ * 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
+ */
+
+#include "adts_header.h"
+#include "avcodec.h"
+#include "codec_internal.h"
+#include "get_bits.h"
+#include "decode.h"
+
+typedef struct FTRContext {
+    AVCodecContext *aac_avctx[64];   // wrapper context for AAC
+    int nb_context;
+    AVPacket *packet;
+    AVFrame *frame;
+} FTRContext;
+
+static av_cold int ftr_init(AVCodecContext *avctx)
+{
+    FTRContext *s = avctx->priv_data;
+    const AVCodec *codec;
+    int ret;
+
+    if (avctx->ch_layout.nb_channels > 64 ||
+        avctx->ch_layout.nb_channels <= 0)
+        return AVERROR(ENOTSUP);
+
+    s->packet = av_packet_alloc();
+    if (!s->packet)
+        return AVERROR(ENOMEM);
+
+    s->frame = av_frame_alloc();
+    if (!s->frame)
+        return AVERROR(ENOMEM);
+
+    s->nb_context = avctx->ch_layout.nb_channels;
+
+    codec = avcodec_find_decoder(AV_CODEC_ID_AAC);
+    if (!codec)
+        return AVERROR_BUG;
+
+    for (int i = 0; i < s->nb_context; i++) {
+        s->aac_avctx[i] = avcodec_alloc_context3(codec);
+        if (!s->aac_avctx[i])
+            return AVERROR(ENOMEM);
+        ret = avcodec_open2(s->aac_avctx[i], codec, NULL);
+        if (ret < 0)
+            return ret;
+    }
+
+    avctx->sample_fmt = s->aac_avctx[0]->sample_fmt;
+    if (!av_sample_fmt_is_planar(avctx->sample_fmt))
+        return AVERROR(EINVAL);
+
+    return 0;
+}
+
+static int ftr_decode_frame(AVCodecContext *avctx, AVFrame *frame,
+                            int *got_frame, AVPacket *avpkt)
+{
+    FTRContext *s = avctx->priv_data;
+    GetBitContext gb;
+    int ret, ch_offset = 0;
+
+    ret = init_get_bits8(&gb, avpkt->data, avpkt->size);
+    if (ret < 0)
+        return ret;
+
+    frame->nb_samples = 0;
+
+    for (int i = 0; i < s->nb_context; i++) {
+        AVCodecContext *codec_avctx = s->aac_avctx[i];
+        GetBitContext gb2 = gb;
+        AACADTSHeaderInfo hdr_info;
+        int size;
+
+        if (get_bits_left(&gb) < 64)
+            return AVERROR_INVALIDDATA;
+
+        memset(&hdr_info, 0, sizeof(hdr_info));
+
+        size = ff_adts_header_parse(&gb2, &hdr_info);
+        if (size <= 0 || size * 8 > get_bits_left(&gb))
+            return AVERROR_INVALIDDATA;
+
+        if (size > s->packet->size) {
+            ret = av_grow_packet(s->packet, size - s->packet->size);
+            if (ret < 0)
+                return ret;
+        }
+
+        ret = av_packet_make_writable(s->packet);
+        if (ret < 0)
+            return ret;
+
+        memcpy(s->packet->data, avpkt->data + (get_bits_count(&gb) >> 3), size);
+        s->packet->size = size;
+
+        if (size > 12) {
+            uint8_t *buf = s->packet->data;
+
+            if (buf[3] & 0x20) {
+                int tmp = buf[8];
+                buf[ 9] = ~buf[9];
+                buf[11] = ~buf[11];
+                buf[12] = ~buf[12];
+                buf[ 8] = ~buf[10];
+                buf[10] = ~tmp;
+            }
+        }
+
+        ret = avcodec_send_packet(codec_avctx, s->packet);
+        if (ret < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Error submitting a packet for decoding\n");
+            return ret;
+        }
+
+        ret = avcodec_receive_frame(codec_avctx, s->frame);
+        if (ret < 0)
+            return ret;
+
+        if (!avctx->sample_rate) {
+            avctx->sample_rate = codec_avctx->sample_rate;
+        } else {
+            if (avctx->sample_rate != codec_avctx->sample_rate)
+                return AVERROR_INVALIDDATA;
+        }
+
+        if (!frame->nb_samples) {
+            frame->nb_samples = s->frame->nb_samples;
+            if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+                return ret;
+        } else {
+            if (frame->nb_samples != s->frame->nb_samples)
+                return AVERROR_INVALIDDATA;
+        }
+
+        skip_bits_long(&gb, size * 8);
+
+        if (ch_offset + s->frame->ch_layout.nb_channels > avctx->ch_layout.nb_channels)
+            return AVERROR_INVALIDDATA;
+
+        if (avctx->sample_fmt != codec_avctx->sample_fmt)
+            return AVERROR_INVALIDDATA;
+
+        for (int ch = 0; ch < s->frame->ch_layout.nb_channels; ch++)
+            memcpy(frame->extended_data[ch_offset + ch],
+                   s->frame->extended_data[ch],
+                   av_get_bytes_per_sample(codec_avctx->sample_fmt) * s->frame->nb_samples);
+
+        ch_offset += s->frame->ch_layout.nb_channels;
+
+        if (ch_offset >= avctx->ch_layout.nb_channels)
+            break;
+    }
+
+    *got_frame = 1;
+
+    return get_bits_count(&gb) >> 3;
+}
+
+static void ftr_flush(AVCodecContext *avctx)
+{
+    FTRContext *s = avctx->priv_data;
+
+    for (int i = 0; i < s->nb_context; i++)
+        avcodec_flush_buffers(s->aac_avctx[i]);
+}
+
+static av_cold int ftr_close(AVCodecContext *avctx)
+{
+    FTRContext *s = avctx->priv_data;
+
+    for (int i = 0; i < s->nb_context; i++)
+        avcodec_free_context(&s->aac_avctx[i]);
+    av_packet_free(&s->packet);
+    av_frame_free(&s->frame);
+
+    return 0;
+}
+
+const FFCodec ff_ftr_decoder = {
+    .p.name         = "ftr",
+    .p.long_name    = NULL_IF_CONFIG_SMALL("FTR Voice"),
+    .p.type         = AVMEDIA_TYPE_AUDIO,
+    .p.id           = AV_CODEC_ID_FTR,
+    .init           = ftr_init,
+    FF_CODEC_DECODE_CB(ftr_decode_frame),
+    .close          = ftr_close,
+    .flush          = ftr_flush,
+    .priv_data_size = sizeof(FTRContext),
+    .p.capabilities = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+};