[FFmpeg-devel] [PATCH] ALS decoder

[Thilo Borgmann]

Michael Niedermayer schrieb:
> On Thu, Sep 03, 2009 at 01:58:11AM +0200, Thilo Borgmann wrote:
> [...]
>>>> +        av_log(ctx->avctx, AV_LOG_WARNING,
>>>> +               "Reading frame data failed. Skipping RA unit.\n");
>>>> +
>>>> +    // increment the frame counter
>>>> +    ctx->frame_id++;
>>>> +
>>>> +    // transform decoded frame into output format
>>>> +    #define INTERLEAVE_OUTPUT(bps)                                 \
>>>> +    {                                                              \
>>>> +        int##bps##_t *dest = (int##bps##_t*) data;                 \
>>>> +        shift = bps - ctx->avctx->bits_per_raw_sample;             \
>>>> +        for (sample = 0; sample < ctx->cur_frame_length; sample++) \
>>>> +            for (c = 0; c < avctx->channels; c++)                  \
>>>> +                *dest++ = ctx->raw_samples[c][sample] << shift;    \
>>>> +    }
>>>> +
>>>> +    if (ctx->avctx->bits_per_raw_sample <= 16) {
>>>> +        INTERLEAVE_OUTPUT(16)
>>>> +    } else {
>>>> +        INTERLEAVE_OUTPUT(32)
>>>> +    }
>>>> +
>>>> +    *data_size = ctx->cur_frame_length * avctx->channels
>>>> +                 * (av_get_bits_per_sample_format(avctx->sample_fmt) >> 3);
>>> data_size is not checked before writing into the buffer
>>>
>>>
>>> ...
>>>
>>>> +    // check for size of decoded data
>>>> +    data_size = sconf->frame_length * avctx->channels *
>>>> +                (av_get_bits_per_sample_format(avctx->sample_fmt) >> 3);
>>>> +
>>>> +    if (data_size > INT_MAX) {
>>>> +        av_log(avctx, AV_LOG_ERROR, "Decoded data exceeds buffer size.\n");
>>>> +        decode_end(avctx);
>>>> +        return -1;
>>>> +    }
>>> whatever this check should do it doesnt work, it wont ever be true as the
>>> multiplications are using int not int64
>> I did this to check data_size before writing into the buffer - you
>> already complained about this. Ok it is wrong as-is but is this a valid
>> test for the case mentioned above if done correctly (MUL64()) or not?
> 
> its not
> what is missing is a
> if(the_number_of_samples_i_will_write > *data_size)
> 

Ok then I got you wrong the first time. Done.


Thanks!

-Thilo