diff options
author | Ivo van Poorten <ivop@euronet.nl> | 2007-04-10 09:15:54 +0000 |
---|---|---|
committer | Ivo van Poorten <ivop@euronet.nl> | 2007-04-10 09:15:54 +0000 |
commit | 201df5a19f3c8773b0da06627dfc51c46a5d40cb (patch) | |
tree | d43df23955541459cd4577f3bffb0980950ed4ad /libavcodec | |
parent | e457023a95e449ac2c80a49256f0611d5a8fffff (diff) | |
download | ffmpeg-streaming-201df5a19f3c8773b0da06627dfc51c46a5d40cb.zip ffmpeg-streaming-201df5a19f3c8773b0da06627dfc51c46a5d40cb.tar.gz |
Add support for grayscale images with arbitrary maxvals.
The image data is rescaled to the nearest pix_fmt it will fit in (gray8 or
gray16). Conversion is done inside the codec in order to avoid the need
for 14 (or 65534) new pix_fmt's.
Originally committed as revision 8704 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
-rw-r--r-- | libavcodec/pnm.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/libavcodec/pnm.c b/libavcodec/pnm.c index 4c9c46f..ffd5d06 100644 --- a/libavcodec/pnm.c +++ b/libavcodec/pnm.c @@ -26,6 +26,7 @@ typedef struct PNMContext { uint8_t *bytestream_start; uint8_t *bytestream_end; AVFrame picture; + int maxval; ///< maximum value of a pixel } PNMContext; static inline int pnm_space(int c) @@ -142,8 +143,12 @@ static int pnm_decode_header(AVCodecContext *avctx, PNMContext * const s){ return -1; if (avctx->pix_fmt != PIX_FMT_MONOWHITE) { pnm_get(s, buf1, sizeof(buf1)); - if(atoi(buf1) == 65535 && avctx->pix_fmt == PIX_FMT_GRAY8) + s->maxval = atoi(buf1); + if(s->maxval >= 256 && avctx->pix_fmt == PIX_FMT_GRAY8) { avctx->pix_fmt = PIX_FMT_GRAY16BE; + if (s->maxval != 65535) + avctx->pix_fmt = PIX_FMT_GRAY16; + } } /* more check if YUV420 */ if (avctx->pix_fmt == PIX_FMT_YUV420P) { @@ -165,7 +170,7 @@ static int pnm_decode_frame(AVCodecContext *avctx, PNMContext * const s = avctx->priv_data; AVFrame *picture = data; AVFrame * const p= (AVFrame*)&s->picture; - int i, n, linesize, h; + int i, n, linesize, h, upgrade = 0; unsigned char *ptr; s->bytestream_start= @@ -194,9 +199,14 @@ static int pnm_decode_frame(AVCodecContext *avctx, goto do_read; case PIX_FMT_GRAY8: n = avctx->width; + if (s->maxval < 255) + upgrade = 1; goto do_read; case PIX_FMT_GRAY16BE: + case PIX_FMT_GRAY16LE: n = avctx->width * 2; + if (s->maxval < 65535) + upgrade = 2; goto do_read; case PIX_FMT_MONOWHITE: case PIX_FMT_MONOBLACK: @@ -207,7 +217,19 @@ static int pnm_decode_frame(AVCodecContext *avctx, if(s->bytestream + n*avctx->height > s->bytestream_end) return -1; for(i = 0; i < avctx->height; i++) { + if (!upgrade) memcpy(ptr, s->bytestream, n); + else if (upgrade == 1) { + unsigned int j, f = (255*128 + s->maxval/2) / s->maxval; + for (j=0; j<n; j++) + ptr[j] = (s->bytestream[j] * f + 64) >> 7; + } else if (upgrade == 2) { + unsigned int j, v, f = (65535*32768 + s->maxval/2) / s->maxval; + for (j=0; j<n/2; j++) { + v = be2me_16(((uint16_t *)s->bytestream)[j]); + ((uint16_t *)ptr)[j] = (v * f + 16384) >> 15; + } + } s->bytestream += n; ptr += linesize; } |