On Thu, Mar 13, 2014 at 04:27:28PM +0100, Vittorio Giovara wrote:
> ---
> Changelog | 1 +
> libavcodec/sgidec.c | 56
> +++++++++++++++++++++++++++++++++++++++++++++++------
> 2 files changed, 51 insertions(+), 6 deletions(-)
>
> diff --git a/Changelog b/Changelog
> index 9b607df..7e46e67 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -6,6 +6,7 @@ version <next>:
> - shuffleplanes filter
> - OpenEXR image decoder
> - support encoding and decoding 4 channel SGI images
> +- support decoding 16 bit RLE SGI images
>
>
> version 10:
> diff --git a/libavcodec/sgidec.c b/libavcodec/sgidec.c
> index be1e1f3..b27d131 100644
> --- a/libavcodec/sgidec.c
> +++ b/libavcodec/sgidec.c
> @@ -43,8 +43,8 @@ typedef struct SgiState {
> * @param pixelstride pixel stride of input buffer
> * @return size of output in bytes, -1 if buffer overflows
> */
> -static int expand_rle_row(SgiState *s, uint8_t *out_buf,
> - int len, int pixelstride)
> +static int expand_rle_row8(SgiState *s, uint8_t *out_buf,
> + int len, int pixelstride)
> {
> unsigned char pixel, count;
> unsigned char *orig = out_buf;
> @@ -81,6 +81,46 @@ static int expand_rle_row(SgiState *s, uint8_t *out_buf,
> return (out_buf - orig) / pixelstride;
> }
>
> +static int expand_rle_row16(SgiState *s, uint16_t *out_buf,
> + int len, int pixelstride)
> +{
> + unsigned short pixel;
> + unsigned char count;
> + unsigned short *orig = out_buf;
> + uint16_t *out_end = out_buf + len;
> +
> + while (out_buf < out_end) {
> + if (bytestream2_get_bytes_left(&s->g) < 1)
should be 2 since you read 2-byte value below
> + return AVERROR_INVALIDDATA;
> + pixel = bytestream2_get_be16u(&s->g);
> + if (!(count = (pixel & 0x7f)))
> + break;
> +
> + /* Check for buffer overflow. */
> + if (pixelstride * (count - 1) >= len) {
> + av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + if (pixel & 0x80) {
makes one wonder why it was 2-byte and the second byte not used anywhere
> + while (count--) {
> + pixel = bytestream2_get_be16(&s->g);
> + AV_WB16(out_buf, pixel);
> + out_buf += pixelstride;
> + }
> + } else {
> + pixel = bytestream2_get_be16(&s->g);
> +
> + while (count--) {
> + AV_WB16(out_buf, pixel);
> + out_buf += pixelstride;
in theory get_ne16()+AV_WN16A should be better
> + }
> + }
> + }
> + return (out_buf - orig) / pixelstride;
> +}
> +
> +
> /**
> * Read a run length encoded SGI image.
> * @param out_buf output buffer
> @@ -94,6 +134,7 @@ static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
> GetByteContext g_table = s->g;
> unsigned int y, z;
> unsigned int start_offset;
> + int linesize, ret;
>
> /* size of RLE offset and length tables */
> if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
> @@ -103,13 +144,16 @@ static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
> for (z = 0; z < s->depth; z++) {
> dest_row = out_buf;
> for (y = 0; y < s->height; y++) {
> + linesize = s->width * s->depth * s->bytes_per_channel;
> dest_row -= s->linesize;
> start_offset = bytestream2_get_be32(&g_table);
> bytestream2_seek(&s->g, start_offset, SEEK_SET);
> - if (expand_rle_row(s, dest_row + z, s->width * s->depth,
> - s->depth) != s->width) {
> + if (s->bytes_per_channel == 1)
> + ret = expand_rle_row8(s, dest_row + z, linesize, s->depth);
> + else
> + ret = expand_rle_row16(s, (uint16_t *)dest_row + z,
> linesize, s->depth);
> + if (ret != s->width)
> return AVERROR_INVALIDDATA;
> - }
> }
> }
> return 0;
> @@ -183,7 +227,7 @@ static int decode_frame(AVCodecContext *avctx,
> s->height = bytestream2_get_be16(&s->g);
> s->depth = bytestream2_get_be16(&s->g);
>
> - if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) {
> + if (s->bytes_per_channel != 1 && s->bytes_per_channel != 2) {
> av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
> return -1;
> }
> --
> 1.8.3.4 (Apple Git-47)
>
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