[FFmpeg-devel,1/3] avcodec/webp: Use uint8_t for code lengths

They are always in the range 0..15, so using an int is not necessary.
Furthermore, using an int would not work if sizeof(int) == 4 as
ff_init_vlc_sparse() can only handle uint8_t, uint16_t and uint32_t
lengths.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
---
 libavcodec/webp.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Andreas Rheinhardt:
> They are always in the range 0..15, so using an int is not necessary.
> Furthermore, using an int would not work if sizeof(int) == 4 as
> ff_init_vlc_sparse() can only handle uint8_t, uint16_t and uint32_t
> lengths.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
> ---
>  libavcodec/webp.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/libavcodec/webp.c b/libavcodec/webp.c
> index 6140c7ea4a..6b53a7f17c 100644
> --- a/libavcodec/webp.c
> +++ b/libavcodec/webp.c
> @@ -243,7 +243,7 @@ static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb)
>          return get_vlc2(gb, r->vlc.table, 8, 2);
>  }
>  
> -static int huff_reader_build_canonical(HuffReader *r, int *code_lengths,
> +static int huff_reader_build_canonical(HuffReader *r, const uint8_t *code_lengths,
>                                         int alphabet_size)
>  {
>      int len = 0, sym, code = 0, ret;
> @@ -324,8 +324,8 @@ static int read_huffman_code_normal(WebPContext *s, HuffReader *hc,
>                                      int alphabet_size)
>  {
>      HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } };
> -    int *code_lengths = NULL;
> -    int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
> +    uint8_t *code_lengths = NULL;
> +    uint8_t code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
>      int i, symbol, max_symbol, prev_code_len, ret;
>      int num_codes = 4 + get_bits(&s->gb, 4);
>  
> @@ -340,7 +340,7 @@ static int read_huffman_code_normal(WebPContext *s, HuffReader *hc,
>      if (ret < 0)
>          goto finish;
>  
> -    code_lengths = av_mallocz_array(alphabet_size, sizeof(*code_lengths));
> +    code_lengths = av_mallocz(alphabet_size);
>      if (!code_lengths) {
>          ret = AVERROR(ENOMEM);
>          goto finish;
> 
Will apply this patchset later today unless there are objections.

- Andreas

> On Oct 26, 2020, at 3:24 PM, Andreas Rheinhardt <andreas.rheinhardt@gmail.com> wrote:
> 
> Andreas Rheinhardt:
>> They are always in the range 0..15, so using an int is not necessary.
>> Furthermore, using an int would not work if sizeof(int) == 4 as

You mean if sizeof(int) != 4 ?

>> ff_init_vlc_sparse() can only handle uint8_t, uint16_t and uint32_t
>> lengths.
>> 
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
>> ---
>> libavcodec/webp.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>> 
>> diff --git a/libavcodec/webp.c b/libavcodec/webp.c
>> index 6140c7ea4a..6b53a7f17c 100644
>> --- a/libavcodec/webp.c
>> +++ b/libavcodec/webp.c
>> @@ -243,7 +243,7 @@ static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb)
>>         return get_vlc2(gb, r->vlc.table, 8, 2);
>> }
>> 
>> -static int huff_reader_build_canonical(HuffReader *r, int *code_lengths,
>> +static int huff_reader_build_canonical(HuffReader *r, const uint8_t *code_lengths,
>>                                        int alphabet_size)
>> {
>>     int len = 0, sym, code = 0, ret;
>> @@ -324,8 +324,8 @@ static int read_huffman_code_normal(WebPContext *s, HuffReader *hc,
>>                                     int alphabet_size)
>> {
>>     HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } };
>> -    int *code_lengths = NULL;
>> -    int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
>> +    uint8_t *code_lengths = NULL;
>> +    uint8_t code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
>>     int i, symbol, max_symbol, prev_code_len, ret;
>>     int num_codes = 4 + get_bits(&s->gb, 4);
>> 
>> @@ -340,7 +340,7 @@ static int read_huffman_code_normal(WebPContext *s, HuffReader *hc,
>>     if (ret < 0)
>>         goto finish;
>> 
>> -    code_lengths = av_mallocz_array(alphabet_size, sizeof(*code_lengths));
>> +    code_lengths = av_mallocz(alphabet_size);
>>     if (!code_lengths) {
>>         ret = AVERROR(ENOMEM);
>>         goto finish;
>> 
> Will apply this patchset later today unless there are objections.
> 
> - Andreas
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"zhilizhao(赵志立)":
> 
> 
>> On Oct 26, 2020, at 3:24 PM, Andreas Rheinhardt <andreas.rheinhardt@gmail.com> wrote:
>>
>> Andreas Rheinhardt:
>>> They are always in the range 0..15, so using an int is not necessary.
>>> Furthermore, using an int would not work if sizeof(int) == 4 as
> 
> You mean if sizeof(int) != 4 ?
> 

Good catch. Fixed locally. Thanks.

- Andreas