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https://git.videolan.org/git/ffmpeg.git
synced 2024-09-12 18:25:57 +02:00
Revert "Avoid overflows when reading pgm files with maxval != 255 and != 65535."
The patch worked on little endian because pgm decoding was broken
but it was not correct in any way.
This reverts commit 7651c0e49b
.
This commit is contained in:
parent
768e40b451
commit
2c046c718a
@ -35,7 +35,6 @@ static int pnm_decode_frame(AVCodecContext *avctx, void *data,
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int i, j, n, linesize, h, upgrade = 0, is_mono = 0;
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unsigned char *ptr;
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int components, sample_len, ret;
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unsigned int maskval = 0;
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s->bytestream_start =
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s->bytestream = (uint8_t *)buf;
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@ -76,10 +75,8 @@ static int pnm_decode_frame(AVCodecContext *avctx, void *data,
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n = avctx->width;
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components=1;
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sample_len=8;
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if (s->maxval < 255) {
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if (s->maxval < 255)
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upgrade = 1;
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maskval = (2 << av_log2(s->maxval)) - 1;
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}
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goto do_read;
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case AV_PIX_FMT_GRAY8A:
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n = avctx->width * 2;
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@ -91,10 +88,8 @@ static int pnm_decode_frame(AVCodecContext *avctx, void *data,
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n = avctx->width * 2;
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components=1;
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sample_len=16;
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if (s->maxval < 65535) {
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if (s->maxval < 65535)
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upgrade = 2;
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maskval = (2 << av_log2(s->maxval)) - 1;
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}
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goto do_read;
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case AV_PIX_FMT_MONOWHITE:
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case AV_PIX_FMT_MONOBLACK:
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@ -141,11 +136,11 @@ static int pnm_decode_frame(AVCodecContext *avctx, void *data,
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else if (upgrade == 1) {
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unsigned int j, f = (255 * 128 + s->maxval / 2) / s->maxval;
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for (j = 0; j < n; j++)
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ptr[j] = ((s->bytestream[j] & maskval) * f + 64) >> 7;
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ptr[j] = (s->bytestream[j] * f + 64) >> 7;
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} else if (upgrade == 2) {
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unsigned int j, v, f = (65535 * 32768 + s->maxval / 2) / s->maxval;
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for (j = 0; j < n / 2; j++) {
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v = av_be2ne16(((uint16_t *)s->bytestream)[j]) & maskval;
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v = av_be2ne16(((uint16_t *)s->bytestream)[j]);
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((uint16_t *)ptr)[j] = (v * f + 16384) >> 15;
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}
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}
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