[FFmpeg-devel] [PATCH 13/16] vmdaudio: simplify vmdaudio_decode_frame() by handling block_type first, then making a single call to vmdaudio_loadsound().

[Ronald S. Bultje]

Hi,

On Wed, Feb 23, 2011 at 2:01 PM, Kostya <kostya.shishkov at gmail.com> wrote:
> On Wed, Feb 23, 2011 at 01:11:10PM -0500, Justin Ruggles wrote:
>>
>> This also adds output buffer size checks for AUDIO and SILENCE block types.
>> ---
>> ?libavcodec/vmdav.c | ? 24 ++++++++++++------------
>> ?1 files changed, 12 insertions(+), 12 deletions(-)
>>
>
>> diff --git a/libavcodec/vmdav.c b/libavcodec/vmdav.c
>> index d0ffa39..446e2c1 100644
>> --- a/libavcodec/vmdav.c
>> +++ b/libavcodec/vmdav.c
>> @@ -506,7 +506,7 @@ static int vmdaudio_decode_frame(AVCodecContext *avctx,
>> ? ? ?const uint8_t *buf = avpkt->data;
>> ? ? ?int buf_size = avpkt->size;
>> ? ? ?VmdAudioContext *s = avctx->priv_data;
>> - ? ?int block_type;
>> + ? ?int block_type, silent_chunks;
>> ? ? ?unsigned char *output_samples = (unsigned char *)data;
>>
>> ? ? ?if (buf_size < 16) {
>> @@ -523,23 +523,23 @@ static int vmdaudio_decode_frame(AVCodecContext *avctx,
>> ? ? ?buf ? ? ?+= 16;
>> ? ? ?buf_size -= 16;
>>
>> - ? ?if (block_type == BLOCK_TYPE_AUDIO) {
>> - ? ? ? ?/* the chunk contains audio */
>> - ? ? ? ?*data_size = vmdaudio_loadsound(s, output_samples, buf, 0, buf_size);
>> - ? ?} else if (block_type == BLOCK_TYPE_INITIAL) {
>> - ? ? ? ?/* initial chunk, may contain audio and silence */
>> + ? ?silent_chunks = 0;
>> + ? ?if (block_type == BLOCK_TYPE_INITIAL) {
>> ? ? ? ? ?uint32_t flags = AV_RB32(buf);
>> - ? ? ? ?int silent_chunks = av_popcount(flags);
>> + ? ? ? ?silent_chunks ?= av_popcount(flags);
>> ? ? ? ? ?buf ? ? ?+= 4;
>> ? ? ? ? ?buf_size -= 4;
>> - ? ? ? ?if(*data_size < (s->block_align*silent_chunks + buf_size) * 2)
>> - ? ? ? ? ? ?return -1;
>> - ? ? ? ?*data_size = vmdaudio_loadsound(s, output_samples, buf, silent_chunks, buf_size);
>> ? ? ?} else if (block_type == BLOCK_TYPE_SILENCE) {
>> - ? ? ? ?/* silent chunk */
>> - ? ? ? ?*data_size = vmdaudio_loadsound(s, output_samples, buf, 1, 0);
>> + ? ? ? ?silent_chunks = 1;
>> + ? ? ? ?buf_size = 0; // should already be zero but set it just to be sure
>> ? ? ?}
>>
>> + ? ?/* ensure output buffer is large enough */
>> + ? ?if (*data_size < (s->block_align*silent_chunks + buf_size) * 2)
>> + ? ? ? ?return -1;
>> +
>> + ? ?*data_size = vmdaudio_loadsound(s, output_samples, buf, silent_chunks, buf_size);
>> +
>> ? ? ?return avpkt->size;
>> ?}
>>
>
> ok

Queued.

Ronald