mpegvideo_parser: fix buffer access beyond end

[ffmpeg] / libavcodec / libopusdec.c

diff --git a/libavcodec/libopusdec.c b/libavcodec/libopusdec.c
index 15fa4934982674e9a7114816d8726e1b9309e997..f603bdf1860b905fd9ed85e829e0f6e47564296e 100644 (file)
--- a/libavcodec/libopusdec.c
+++ b/libavcodec/libopusdec.c
@@ -2,20 +2,20 @@
  * Opus decoder using libopus
  * Copyright (c) 2012 Nicolas George
  *
- * This file is part of Libav.
+ * This file is part of FFmpeg.
  *
- * Libav is free software; you can redistribute it and/or
+ * 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.
  *
- * Libav is distributed in the hope that it will be useful,
+ * 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 Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -33,6 +33,10 @@
 struct libopus_context {
     OpusMSDecoder *dec;
     AVFrame frame;
+    int pre_skip;
+#ifndef OPUS_SET_GAIN
+    union { int i; double d; } gain;
+#endif
 };
 
 #define OPUS_HEAD_SIZE 19
@@ -50,6 +54,7 @@ static av_cold int libopus_decode_init(AVCodecContext *avc)
                           ff_vorbis_channel_layouts[avc->channels - 1];
 
     if (avc->extradata_size >= OPUS_HEAD_SIZE) {
+        opus->pre_skip = AV_RL16(avc->extradata + 10);
         gain_db     = sign_extend(AV_RL16(avc->extradata + 16), 16);
         channel_map = AV_RL8 (avc->extradata + 18);
     }
@@ -74,7 +79,7 @@ static av_cold int libopus_decode_init(AVCodecContext *avc)
         const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[avc->channels - 1];
         int ch;
 
-        /* Remap channels from vorbis order to libav order */
+        /* Remap channels from vorbis order to ffmpeg order */
         for (ch = 0; ch < avc->channels; ch++)
             mapping_arr[ch] = mapping[vorbis_offset[ch]];
         mapping = mapping_arr;
@@ -89,11 +94,22 @@ static av_cold int libopus_decode_init(AVCodecContext *avc)
         return ff_opus_error_to_averror(ret);
     }
 
+#ifdef OPUS_SET_GAIN
     ret = opus_multistream_decoder_ctl(opus->dec, OPUS_SET_GAIN(gain_db));
     if (ret != OPUS_OK)
         av_log(avc, AV_LOG_WARNING, "Failed to set gain: %s\n",
                opus_strerror(ret));
+#else
+    {
+        double gain_lin = pow(10, gain_db / (20.0 * 256));
+        if (avc->sample_fmt == AV_SAMPLE_FMT_FLT)
+            opus->gain.d = gain_lin;
+        else
+            opus->gain.i = FFMIN(gain_lin * 65536, INT_MAX);
+    }
+#endif
 
+    avc->internal->skip_samples = opus->pre_skip;
     avc->delay = 3840;  /* Decoder delay (in samples) at 48kHz */
     avcodec_get_frame_defaults(&opus->frame);
     avc->coded_frame = &opus->frame;
@@ -138,6 +154,21 @@ static int libopus_decode(AVCodecContext *avc, void *frame,
         return ff_opus_error_to_averror(nb_samples);
     }
 
+#ifndef OPUS_SET_GAIN
+    {
+        int i = avc->channels * nb_samples;
+        if (avc->sample_fmt == AV_SAMPLE_FMT_FLT) {
+            float *pcm = (float *)opus->frame.data[0];
+            for (; i > 0; i--, pcm++)
+                *pcm = av_clipf(*pcm * opus->gain.d, -1, 1);
+        } else {
+            int16_t *pcm = (int16_t *)opus->frame.data[0];
+            for (; i > 0; i--, pcm++)
+                *pcm = av_clip_int16(((int64_t)opus->gain.i * *pcm) >> 16);
+        }
+    }
+#endif
+
     opus->frame.nb_samples = nb_samples;
     *(AVFrame *)frame = opus->frame;
     *got_frame_ptr = 1;
@@ -149,6 +180,9 @@ static void libopus_flush(AVCodecContext *avc)
     struct libopus_context *opus = avc->priv_data;
 
     opus_multistream_decoder_ctl(opus->dec, OPUS_RESET_STATE);
+    /* The stream can have been extracted by a tool that is not Opus-aware.
+       Therefore, any packet can become the first of the stream. */
+    avc->internal->skip_samples = opus->pre_skip;
 }
 
 AVCodec ff_libopus_decoder = {