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| author | Max Kellermann <max@duempel.org> | 2009-11-15 17:39:09 +0100 |
|---|---|---|
| committer | Max Kellermann <max@duempel.org> | 2009-11-15 17:39:09 +0100 |
| commit | 77b95d08a55a35bc966b9a9096cd926c315d49b8 (patch) | |
| tree | 03c42feae1692094bc7e1efafa104cbc64e6911b /src | |
| parent | dca4d9cf83849877206379a20a1e478ed1b5dc55 (diff) | |
| download | mpd-77b95d08a55a35bc966b9a9096cd926c315d49b8.tar.gz mpd-77b95d08a55a35bc966b9a9096cd926c315d49b8.tar.xz mpd-77b95d08a55a35bc966b9a9096cd926c315d49b8.zip | |
decoder/ffmpeg: align the output buffer
On some platforms, libavcodec wants the output buffer aligned to 16
bytes (because it uses SSE/Altivec internally). It will segfault when
you don't obey this rule.
Diffstat (limited to 'src')
| -rw-r--r-- | src/decoder/ffmpeg_plugin.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/src/decoder/ffmpeg_plugin.c b/src/decoder/ffmpeg_plugin.c index 2f7ed6d1f..b9aafaf7b 100644 --- a/src/decoder/ffmpeg_plugin.c +++ b/src/decoder/ffmpeg_plugin.c @@ -209,6 +209,21 @@ ffmpeg_helper(struct input_stream *input, return ret; } +/** + * On some platforms, libavcodec wants the output buffer aligned to 16 + * bytes (because it uses SSE/Altivec internally). This function + * returns the aligned version of the specified buffer, and corrects + * the buffer size. + */ +static void * +align16(void *p, size_t *length_p) +{ + unsigned add = 16 - (size_t)p % 16; + + *length_p -= add; + return (char *)p + add; +} + static enum decoder_command ffmpeg_send_packet(struct decoder *decoder, struct input_stream *is, const AVPacket *packet, @@ -217,7 +232,9 @@ ffmpeg_send_packet(struct decoder *decoder, struct input_stream *is, { enum decoder_command cmd = DECODE_COMMAND_NONE; int position; - uint8_t audio_buf[(AVCODEC_MAX_AUDIO_FRAME_SIZE * 3) / 2]; + uint8_t audio_buf[(AVCODEC_MAX_AUDIO_FRAME_SIZE * 3) / 2 + 16]; + int16_t *aligned_buffer; + size_t buffer_size; int len, audio_size; uint8_t *packet_data; int packet_size; @@ -225,11 +242,13 @@ ffmpeg_send_packet(struct decoder *decoder, struct input_stream *is, packet_data = packet->data; packet_size = packet->size; + buffer_size = sizeof(audio_buf); + aligned_buffer = align16(audio_buf, &buffer_size); + while ((packet_size > 0) && (cmd == DECODE_COMMAND_NONE)) { - audio_size = sizeof(audio_buf); + audio_size = buffer_size; len = avcodec_decode_audio2(codec_context, - (int16_t *)audio_buf, - &audio_size, + aligned_buffer, &audio_size, packet_data, packet_size); if (len < 0) { @@ -250,7 +269,7 @@ ffmpeg_send_packet(struct decoder *decoder, struct input_stream *is, : 0; cmd = decoder_data(decoder, is, - audio_buf, audio_size, + aligned_buffer, audio_size, position, codec_context->bit_rate / 1000, NULL); } |