allow WebPINewRGB/YUVA to be passed a NULL output buffer.

If a NULL pre-allocated buffer is passed, a buffer will be automatically
allocated.

+ add some parameter checks.

reported in http://code.google.com/p/webp/issues/detail?id=139

Change-Id: I9e14ed97db30ee12e46b5e92aac7eeaaeb99bfd5
This commit is contained in:
Pascal Massimino
2013-01-25 02:04:01 -08:00
parent 126c035f3f
commit b7adf37621
3 changed files with 54 additions and 12 deletions

View File

@ -269,19 +269,27 @@ WEBP_EXTERN(WebPIDecoder*) WebPINewDecoder(WebPDecBuffer* output_buffer);
// will output the RGB/A samples specified by 'csp' into a preallocated
// buffer 'output_buffer'. The size of this buffer is at least
// 'output_buffer_size' and the stride (distance in bytes between two scanlines)
// is specified by 'output_stride'. Returns NULL if the allocation failed.
// is specified by 'output_stride'.
// Additionally, output_buffer can be passed NULL in which case the output
// buffer will be allocated automatically when the decoding starts. The
// colorspace 'csp' is taken into account for allocating this buffer. All other
// parameters are ignored.
// Returns NULL if the allocation failed, or if some parameters are invalid.
WEBP_EXTERN(WebPIDecoder*) WebPINewRGB(
WEBP_CSP_MODE csp,
uint8_t* output_buffer, size_t output_buffer_size, int output_stride);
// This function allocates and initializes an incremental-decoder object, which
// will output the raw luma/chroma samples into a preallocated planes. The luma
// plane is specified by its pointer 'luma', its size 'luma_size' and its stride
// 'luma_stride'. Similarly, the chroma-u plane is specified by the 'u',
// 'u_size' and 'u_stride' parameters, and the chroma-v plane by 'v'
// and 'v_size'. And same for the alpha-plane. The 'a' pointer can be pass
// NULL in case one is not interested in the transparency plane.
// Returns NULL if the allocation failed.
// will output the raw luma/chroma samples into a preallocated planes if
// supplied. The luma plane is specified by its pointer 'luma', its size
// 'luma_size' and its stride 'luma_stride'. Similarly, the chroma-u plane
// is specified by the 'u', 'u_size' and 'u_stride' parameters, and the chroma-v
// plane by 'v' and 'v_size'. And same for the alpha-plane. The 'a' pointer
// can be pass NULL in case one is not interested in the transparency plane.
// Conversely, 'luma' can be passed NULL if no preallocated planes are supplied.
// In this case, the output buffer will be automatically allocated (using
// MODE_YUVA) when decoding starts. All parameters are then ignored.
// Returns NULL if the allocation failed or if a parameter is invalid.
WEBP_EXTERN(WebPIDecoder*) WebPINewYUVA(
uint8_t* luma, size_t luma_size, int luma_stride,
uint8_t* u, size_t u_size, int u_stride,