[FFmpeg-devel] Patch to fix qtrle endian issue with rgb555 pixel format

[Mo DeJong]

I tried that, but it did not work. It would always default back to rgb24.

Mo DeJong

On Sun, Feb 28, 2010 at 12:05 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Sat, Feb 27, 2010 at 07:16:35PM -0800, Mo DeJong wrote:
>> The attached patch fixes encoding to a rle555 (thousands of colors)
>> pixel format with the qtrle video codec.
>>
>> $ ffmpeg -y -i m1b1BPR_QTPRO_16bpp.mov -vcodec qtrle -pix_fmt rgb555
>> m1b1BPR_FFMPEG_16bpp_reexport.mov
>>
>> ? Duration: 00:00:01.50, start: 0.000000, bitrate: 4 kb/s
>> ? ? Stream #0.0(eng): Video: qtrle, rgb555le, 1x1, 0 kb/s, 2 fps, 2
>> tbr, 1k tbn, 1k tbc
>> Output #0, mov, to 'm1b1BPR_FFMPEG_16bpp_reexport.mov':
>> ? Metadata:
>> ? ? encoder ? ? ? ? : Lavf52.54.0
>> ? ? Stream #0.0(eng): Video: qtrle, rgb555le, 1x1, q=2-31, 200 kb/s, 2
>> tbn, 2 tbc
>>
>> The problem was that pixels were being written in native endian
>> (little) format when they should have been written as big endian.
>>
>> cheers
>> Mo DeJong
>
>> ?qtrleenc.c | ? 29 ++++++++++++++++++++++++-----
>> ?1 file changed, 24 insertions(+), 5 deletions(-)
>> 8ddbabc9567475af8bba0ddaadf1c25894db95ac ?qtrle_rgb555.patch
>> diff --git a/libavcodec/qtrleenc.c b/libavcodec/qtrleenc.c
>> index eb275d4..b39a95b 100644
>> --- a/libavcodec/qtrleenc.c
>> +++ b/libavcodec/qtrleenc.c
>> @@ -58,6 +58,25 @@ typedef struct QtrleEncContext {
>> ? ? ?uint8_t* skip_table;
>> ?} QtrleEncContext;
>>
>> +static void qtrle_write_pixels(uint8_t **b, const uint8_t *src, unsigned int size, int pixel_size) {
>> + ? ?if (pixel_size == 2) {
>> + ? ? ? ?/* writing a 16 bit rgb555 has to take endian issues into account, convert to BE on LE machines */
>> + ? ? ? ?uint16_t inPixel;
>> + ? ? ? ?uint16_t outPixel;
>> + ? ? ? ?const int pixel_count = size / 2;
>> + ? ? ? ?uint16_t *outBuffer = av_mallocz(size);
>> + ? ? ? ?for (int i = 0; i < pixel_count; i++) {
>> + ? ? ? ? ? ?inPixel = *((((const uint16_t*) src) + i));
>> + ? ? ? ? ? ?AV_WB16(&outPixel, inPixel);
>> + ? ? ? ? ? ?*outBuffer = outPixel;
>> + ? ? ? ?}
>> + ? ? ? ?bytestream_put_buffer(b, (const uint8_t *)outBuffer, size);
>> + ? ? ? ?av_free(outBuffer);
>> + ? ?} else {
>> + ? ? ? ?bytestream_put_buffer(b, src, size);
>> + ? ?}
>> +}
>> +
>> ?static av_cold int qtrle_encode_init(AVCodecContext *avctx)
>> ?{
>> ? ? ?QtrleEncContext *s = avctx->priv_data;
>> @@ -68,9 +87,9 @@ static av_cold int qtrle_encode_init(AVCodecContext *avctx)
>> ? ? ?s->avctx=avctx;
>>
>> ? ? ?switch (avctx->pix_fmt) {
>> -/* ? ?case PIX_FMT_RGB555:
>> + ? ?case PIX_FMT_RGB555:
>> ? ? ? ? ?s->pixel_size = 2;
>> - ? ? ? ?break;*/
>> + ? ? ? ?break;
>> ? ? ?case PIX_FMT_RGB24:
>> ? ? ? ? ?s->pixel_size = 3;
>> ? ? ? ? ?break;
>> @@ -223,12 +242,12 @@ static void qtrle_encode_line(QtrleEncContext *s, AVFrame *p, int line, uint8_t
>> ? ? ? ? ?}
>> ? ? ? ? ?else if (rlecode > 0) {
>> ? ? ? ? ? ? ?/* bulk copy */
>> - ? ? ? ? ? ?bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
>> + ? ? ? ? ? ?qtrle_write_pixels(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size, s->pixel_size);
>> ? ? ? ? ? ? ?i += rlecode;
>> ? ? ? ? ?}
>> ? ? ? ? ?else {
>> ? ? ? ? ? ? ?/* repeat the bits */
>> - ? ? ? ? ? ?bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
>> + ? ? ? ? ? ?qtrle_write_pixels(buf, this_line + i*s->pixel_size, s->pixel_size, s->pixel_size);
>> ? ? ? ? ? ? ?i -= rlecode;
>> ? ? ? ? ?}
>> ? ? ?}
>> @@ -328,6 +347,6 @@ AVCodec qtrle_encoder = {
>> ? ? ?qtrle_encode_init,
>> ? ? ?qtrle_encode_frame,
>> ? ? ?qtrle_encode_end,
>> - ? ?.pix_fmts = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_ARGB, PIX_FMT_NONE},
>> + ? ?.pix_fmts = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_ARGB, PIX_FMT_RGB555, PIX_FMT_NONE},
>
> why not:
>
> -PIX_FMT_RGB555
> +PIX_FMT_RGB555BE
>
> ?
>
>
>
> [...]
> --
> Michael ? ? GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Incandescent light bulbs waste a lot of energy as heat so the EU forbids them.
> Their replacement, compact fluorescent lamps, much more expensive, dont fit in
> many old lamps, flicker, contain toxic mercury, produce a fraction of the light
> that is claimed and in a unnatural spectrum rendering colors different than
> in natural light. Ah and we now need to turn the heaters up more in winter to
> compensate the lower wasted heat. Who wins? Not the environment, thats for sure
>
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